FYI: based on comments to this post, it appears this only works with 32-bit Outlook (OS can be either 32-bit or 64-bit), so if you’re running 64-bit Outlook and don’t want to reinstall to the 32-bit version, check some of the other options listed in the comments.
Until the official Google Calendar Sync supports 2010, you’re stuck either living without it, or using one of the ‘hack’ methods to get it working.
NOTE: this post is more detailed than it needs to be – consider yourself warned 
The ones that show up time and again on the support forum thread for this are:
- using a hacked version of GoogleCalendarSync.exe
- hacking your version of Outlook.exe
IMPORTANT: you only need to do one of these, NOT BOTH. Using the hacked Google Calendar Sync is certainly the easier of the two options. I include the “hack your Outlook.exe” option more for completeness, although there may be readers that are more willing to modify their Outlook.exe than to run the hacked sync exe they download. However, both work just fine in my testing.
Hacking GoogleCalendarSync.exe
This is certainly the easier approach of the two.
- Install Google Calendar Sync the way you normally would: http://dl.google.com/googlecalendarsync/GoogleCalendarSync_Installer.exe
- Download this zip file: http://mychannellogos.com/Documents/GoogleCalendarSync.zip
- IMPORTANT: unblock the zip file before extracting the file from it.
- Go to the folder that contains the zip file after you downloaded it
- Right-click on the zip file and select Properties (or alt-double-click or alt-enter or whatever)
- Click Unblock
- Click OK
- NOTE: if you forget this step – you could always unblock the exe after extraction, but I like to unblock the zip in case I want to re-extract the exe again later on.
- Extract/copy the GoogleCalenderSync.exe from the zip over to your <Program Files>\Google\Google Calender Sync
- You probably want to make a backup copy of the existing exe first, just in case, although if you forget and want it back, you can obviously just reinstall it.
One concern people might have is using some random exe off the internet in this way. Just to check, I did a binary diff. Well, I tried to use the diff.exe that came with (g)vim, but –binary just said they were different instead of giving me something like a breakdown of byte differences. Rather than fight with it, I just sucked the 2 exe’s into byte arrays to compare:
[180] C:\Program Files\Google\Google Calendar Sync » $new = gc -encoding byte .\GoogleCalendarSync.exe
[181] C:\Program Files\Google\Google Calendar Sync » $old = gc -encoding byte .\GoogleCalendarSync.exe.orig
[184] C:\Program Files\Google\Google Calendar Sync » compare $old $newInputObject SideIndicator
———– ————-
235 =>
117 <=
So, hacked version has a byte of 0xEB where the orig has 0×75 – didn’t see an obvious way out of compare to get the offset, so did the obvious/lazy way
[204] C:\Program Files\Google\Google Calendar Sync » foreach ($i in 1 .. $old.length) { if (compare $old[$i] $new[$i]) { $i } }
185732
[205] C:\Program Files\Google\Google Calendar Sync » ‘{0:x}’ -f 185732
2d584
With Notepad++ using the Hex Editor plugin, you can see them with the surrounding bytes:
What does that byte change? Well, let’s look at it in VS, by starting the orig exe (probably a way to get the disassembly in VS without the running process, but I know this way already , attaching the debugger, and going to that offset. Since the exe loads at 0×00400000 (checking Debug –> Windows –> Modules), I need to add the offset to that to get the right memory location of 0x0042D584.
Going to that spot in memory in the disassembly shows it’s a jne instruction:
Setting a breakpoint there and then stepping once, we can see in the orig exe case, the failure case doesn’t take that jump:
If we let it run (F5) from there, we get the error dialog that everyone that’s hit this is familiar with:
So what about the hacked version of the exe? What does that one byte change do?
You can likely guess it based on the above behavior – it
just makes the jump unconditional, ignoring the result of the compare:
So, hopefully that will help clear up any fear that the modified exe is doing something nefarious – it’s no more nefarious than the original exe
Hacking Outlook.exe
This one’s a little more difficult than the above, simply because you most likely want to use a hex editor to make this change rather than trying to do so by loading the exe into a normal text editor. As with the previous approach, you likely want to make a backup copy of the .exe before modifying it.
The file you want to edit is the 2010 version, so make sure to edit the one in <Program Files>\Microsoft Office\Office14 (if you still have other versions installed, you’ll have other outlook.exe files in other folders).
What if you don’t have a hex editor handy but still want to take this approach? There’s tons of hex editors out there, but since it’s what I happened to pick for this example, I’ll mention the steps for Notepad++
- Install Notepad++
- Main site: http://notepad-plus.sourceforge.net/
- Files area: http://sourceforge.net/projects/notepad-plus/files/
- IMHO, you’ll want the installer exe – just click the green button here on this page:
- Install Hex Editor plugin
- Nice thing about Notepad++ is that it has a Plugin Manager that lists both installed and available plugins.
- The unfortunate thing is that, at least at the moment, the Hex Editor plugin is not considered stable, so to get it to show in the list of Available plugins, you need to click on the Settings button…
- … and then check “Show unstable plugins”
- With that checked, HEX-Editor will then show up in the list of available plugins:
- Check the box next to it, click the Install button, and then let Notepad++ restart when the Plugin Manager prompts you to do so:
For now, I’ll just assume you’re using Notepad++ with the hex editor plugin – as I mentioned, there’s plenty of others, so feel free to use another if you want – the instructions aren’t appreciably different.
Open the Outlook.exe file in Notepad++ (make sure Outlook is not running – you can do this in any of the usual ways, including:
- drag-and-drop the file from explorer into the running app
- right-click Outlook.exe and select “Edit with Notepad++”
- File –> Open (or Control+O) and browse around and select the file
When initially opened up, you’re not in the hex view yet, so you get the text editor view with lots of embedded nulls:
Site note: For those who don’t already know – the magic number at the front – the ASCII letters ‘MZ’, are because of Mark Zbikowski
You instead want to look at the hex view of the file, so we select “View in Hex” from the plugin’s submenu:
Thankfully finding the place in the file to modify is pretty simple – just look for the (ANSI/ASCII) string “14.0.0” – it happens to be prefixed with an open paren, but even if you leave that out of the search string, there’s only 1 match (at least in my version, 14.0.4536.1000, 32-bit, but it appears true for other builds based on the forum thread).
In Notepad++, you can bring up the find window with Control+F. The first thing you’ll want to do is change the data type to “ANSI String”:
Once that’s changed, we can put in the search string of 14.0.0:
Click Find Next and you’ll get to the match (only one in the file, at least in my versi
on):
Change the “14” to “12”. Easiest way is clicking just before the “4” in the right-hand column and then typing “2” to overwrite it – resulting in:
(ignore the underlined part on the left side – that just shows you the byte that’s just to the right of the cursor – the one you would potentially be overwriting).
As you can see, the byte “34” changed to “32” in the hex view (left side).
Now, just save the file, start Outlook, then tell Google Calendar Sync to go ahead and do a sync now just to make sure it works:
Of course, add an appointment on each side (google calendar and outlook) then do another sync to make sure it copies both ways
That’s it – since both ways work for me, hopefully at least one of them will work for you
OS Vista Ultimate. MSO2010beta. Your idea to Sync Calendar Rockzzzzzz…!!
Any suggestion to sync contacts, notes…??
Glad to Comment
Comment by Sra — March 22, 2010 @ 2:16 pm
This is what I was looking for!! thanks a lot!! =D
It’s really safe to mod google calendar’s file INSTEAD of modding outlook’s build number…
Comment by Raul — April 26, 2010 @ 1:49 pm
Any idea if this will work for 64 bit versions of Outlook 2010 RTM?
Trying to think up a way to test that won’t require hours of backing out if it doesn’t work but haven’t figured that out yet.
Comment by Ryan Baker — April 28, 2010 @ 1:25 am
both should work fine for 64-bit as well (since the route of modifying the outlook binary is a version string, not code), but I’d stick with trying the modified calendar first.
For testing it, just try the modified calendar sync exe – run it, create a new appt in Outlook called ‘foo’, create a new appt in google calendar called ‘bar’, then sync
Backing out is just putting the unmodified .exe back into place (which you wouldn’t really need to do – the modification is just around a version check).
Comment by manningj — April 28, 2010 @ 6:16 am
No joy. I tried it on a second PC and with 2010 64-bit Outlook and the calendar hack I get the following error when I try to perform a sync:
“Could not connect to Microsoft Outlook tm: error -2147024156 …”
Comment by Ryan Baker — April 29, 2010 @ 3:32 am
Works like a dream – well done! I reckon it’s way easier to alter google sync than Outlook. I’m running Win 7 64 bit and Outlook 2010 32 bit.
Comment by Jim — April 30, 2010 @ 11:59 am
Using the hacked Google sync utility worked for me (Outlook 2010 32-bit) *except* that appts I accept from other people are not synced to Google. If I create the appt myself and sync it, it works fine. Anyone have a different experience?
Comment by Tom — May 6, 2010 @ 12:24 pm
works fine for me (32-bit 2010, but I’m still using the beta). Anything weird about your meeting accepts? (like, are they still marked as busy instead of tentative or free?)
The only reason I know for sure is that I had made a entry on my google calendar for a 2pm mtg this past Tuesday and then on Monday I got an invite – I ended up accepting it in Outlook and then it had conflicting entries in google calendar after it did a sync.
Note that in general it’s ‘better’ to create (and I would assume accept) in Google because of the reminders (well, assuming you use email and/or SMS reminders).
http://www.google.com/support/calendar/bin/static.py?page=troubleshooter.cs&problem=techissue&selected=techissue_event_reminders&sl=olsync03&ctx=techissue_techissue_event_reminders_89972
Comment by manningj — May 6, 2010 @ 2:03 pm
Great! I’ve tried both methods and the new Google Calendar sync code works better. For some reason, the hexed Outlook.exe file causes the system to run slowly.
Comment by techrev — May 8, 2010 @ 8:09 pm
Office 2010 Pro final release 64 bit.
It doesn’t work.
google sync gives error:
Could not initialize Google Calendar Sync add-in for Microsoft Outlook: Code 1011.
Comment by Ken — May 10, 2010 @ 4:11 pm
Yep, same here with the same configuration – this was from using the hacked copy of GCS, haven’t tried the Outlook hack yet
Comment by Matt — May 11, 2010 @ 7:28 am
Ditto here. “Could not initialize Google Calendar Sync add-in for Microsoft Outlook: Code 1011.”
Office 2010 Pro Plus 64-bit
Windows 7 64-bit
Comment by Lars-UT — May 18, 2010 @ 4:15 pm
same here same code: running windows 7 64-bit: Could not initialize Google Calendar Sync add-in for Microsoft Outlook: Code 1011.
Comment by johnny — June 3, 2010 @ 2:26 am
no luck with w7-64, Outlook2010pro-64: the same code 1011.
vince
Comment by vince — June 3, 2010 @ 5:49 am
GSync hack works great. Thanks for the write up! Much appreciated.
Comment by Dave — May 11, 2010 @ 6:11 am
Thanks for the fix. Worked fine for me w/ Win7 & OL2010 both 32 bit.
I also did a binary compare using BeyondCompare and the only change I see is was what is described in this post.
Comment by Erik Lane — May 11, 2010 @ 9:41 pm
[...] via James Manning’s Blog [...]
Pingback by Cum se face: sincronizare calendar Outlook 2010 – Google Calendar | CHIP Go Digital Blog — May 13, 2010 @ 3:58 am
SAME HERE…
Office 2010 Pro final release 64 bit.
It doesn’t work.
google sync gives error:
Could not initialize Google Calendar Sync add-in for Microsoft Outlook: Code 1011.
Comment by Mark Augustin — May 14, 2010 @ 8:48 am
when i tell people i still use 32-bit apps (and in most cases, a 32-bit OS) and they ask why, it’s things like this that I point to
Comment by manningj — May 14, 2010 @ 9:52 am
dude, I love you !!!
Comment by rafabytes — May 15, 2010 @ 5:46 pm
[...] http://blog.sublogic.com/2010/03/08/getting-google-calendar-sync-to-work-with-outlook-2010/ – The internet wins again. #yay # [...]
Pingback by the missing link~ » the missing tweets~ [2010-05-17] — May 17, 2010 @ 3:37 am
Good stuff, thanks!
Comment by Ben — May 18, 2010 @ 10:54 pm
[...] Getting Google Calendar Sync to work with Outlook 2010 « James Manning’s Blog. [...]
Pingback by Getting Google Calendar Sync to work with Outlook 2010 - Inane World — May 28, 2010 @ 11:10 am
[...] 2 possible ‘fixes’ were to either hack the GoogleCalendarSync.exe or Outlook.exe (see this post for details). However, I decided not to go that route; instead I installed Sync2 from 4Team [...]
Pingback by Outlook 2010 – First Impressions « Evergreen Technology Corporation — May 28, 2010 @ 3:39 pm
it works great, thanks.
Comment by jorge mario — June 1, 2010 @ 4:18 pm
Great blend of practical solution and technical schooling, though I don’t see a need to justify the later without leaving the rest of us a checksum to ease our concerns.
Comment by Josh Habdas — June 7, 2010 @ 11:22 pm
I thought about it, but when Outlook gets patched, I didn’t want people editing the patched version to get a checksum mismatch and freak out. Of course, that’s indeed another good reason (among others) to use the former route instead of the latter
Comment by manningj — June 8, 2010 @ 9:20 am
I installed Office 2010 on Windows Vista x64 this past weekend and have been having a problem with Google Calendar Sync ever since. These are the most detailed, easy instructions to follow that I have found on the internet to address this issue. Thanks so much!
Comment by Brent MacAloney — June 8, 2010 @ 9:59 am
You’re quite welcome
Comment by manningj — June 8, 2010 @ 1:16 pm
Since the Google Sync application is the one with the problem, I agree that is one to modify. For those still afraid of downloading an exe, the information provided shows exactly what byte to change in the GoogleCalendarSync.exe via hex editor: navigate to 0002d580 and change 75 to eb.
Comment by clr31 — June 10, 2010 @ 12:09 pm
Thanks … a million thanks. I’m not a computer novice nor expert. I have tried everything everyone has suggested to sync google calendar with outlook 2010. This was easy and it works flawlessly. Thanks. Makes me mad at google for not doing this … obviously it can be done.
Comment by emory — June 10, 2010 @ 7:12 pm
I’m also dead now that I have Office 2010. Office 2007 worked fine with the havked version before.
Comment by Jeff Wonser — June 12, 2010 @ 8:45 pm
Can anyone get the the Google Calendar Sync hack to work with Outlook 2010 640 bit and Win 7 64 bit? I can not get it to work.
Comment by upsidedown — June 13, 2010 @ 10:35 pm
Ignore my previous comment. The Google Calendar Hack seems to work. I had some issues with UAC that I needed to correct
Comment by upsidedown — June 13, 2010 @ 11:27 pm
[...] [...]
Pingback by Outlook 2010 and Pre Synching - PreCentral Forums — June 14, 2010 @ 9:42 am
Modified GoogleSync exe works great. Many thanks.
Comment by S Herring — June 15, 2010 @ 9:54 pm
Using the altered version of the sync tool worked for me! (32 bit)
Thanks for collating that info, working it out and explaining so well.
Cheers!
Toby
Comment by Toby Martini — June 15, 2010 @ 11:09 pm
[...] Here is the link with all the details: http://blog.sublogic.com/2010/03/08/getting-google-calendar-sync-to-work-with-outlook-2010/ [...]
Pingback by How to sync Outlook 2010 with Android phones « Ioannis — June 16, 2010 @ 1:56 pm
Great that you guys figured it all out. Now for a novice like me I’m always looking for the easy way out. So has any one developed a litle downladable program to do all this? I’m runing windows 7 64 bit with Outlook 2010 32 bit. I would be happy to pay a reasonable fee.
Many thanks in advance.
Comment by Chip` — June 19, 2010 @ 12:31 pm
all you have to do is download the already-modified google calendar sync exe and replace the original exe with the modified exe – the part of manually modifying the Outlook exe isn’t necessary if you run the modified calendar sync
Comment by manningj — June 20, 2010 @ 12:23 pm
fantastic, and great job man,
appreciated and thank you….
Comment by walid — June 20, 2010 @ 8:13 am
For my w7-64 and OL2010-64 bit combination, I tried hacking either Calender sync or Outlook.exe and neither worked. Is there any workout for it?
Comment by vince — June 23, 2010 @ 12:58 am
I went with gSyncit. It’s olny 15$ and works like a charm. http://www.daveswebsite.com/software/gsync/index.shtml
Comment by Mark Augustin — June 23, 2010 @ 1:21 am
Thanks for the tip. It doesn’t quite work 100% for me though, and I can’t find anyone else having the same problem. Maybe one of you will know:
When Outlook 2010 is open it will sync every 10 minutes in the background, no problem. But when Outlook is closed and it tries to sync every 10 mins a “Choose Profile” window pops up. I only have one profile, and even when I select the make default tick-box, sure enough 10 minutes later the window pops up again. This means that if I am not at my computer my it won’t sync automatically.
Anyone come across the same issue? Would appreciate your help!
Cheers.
Alexander
Comment by Alexander — June 23, 2010 @ 8:42 am
I’ve seen the behavior, but I’m almost always running Outlook so I haven’t really bothered with it (I also have multiple profiles).
I’d imagine you could switch it over (to stop prompting) Start -> Control Panel -> User Accounts and Family Safety -> Mail and choose the ‘Always use this profile’ radio button.
Comment by manningj — June 23, 2010 @ 9:40 am
Would you be so kind to explain how I would go about switching that over? Bit of a novice here!
Cheers.
Comment by Alexander — June 23, 2010 @ 9:49 am
Actually, I’ve figured out what you meant above. When I get to that option, it is already selected. There are two options: 1. Prompt for a profile to be used and 2. Always use this profile. The latter is what was selected, and still is. Still the same problem though…
Any other ideas?
Comment by Alexander — June 23, 2010 @ 10:01 am
Darn – sorry that didn’t work – any chance there’s a second profile (check the drop-down) that’s maybe defined and not used? If so, delete it
If not, I guess all I’d have left is ‘leave Outlook running’ 
Comment by manningj — June 23, 2010 @ 10:08 am
Definitely no other profiles there. Annoying. Hopefully Google brings out an update soon! Thanks for your help though.
Comment by Alexander — June 23, 2010 @ 10:25 am
I found this by mistake. If you install MobileMe (from Apple), the profile prompt doesn’t come up. Weird. Not sure why that is, you don’t even need to configure MobileMe to do anything, just having it installed gets around this profile prompt issue with office 2010 x86 and this googlesync hack. I hope this helps someone.
Comment by Kevin D — July 5, 2010 @ 6:56 pm
For me it has worked just fine with just hack google calendar, not
was necessary to change the outlook.exe. I’m using MS Office Professional Plus 2010 32bits and Windows 7 Professional 64bits.
Thanks for the tip! great job.
Comment by Filipe Sizilio — June 23, 2010 @ 3:48 pm
Any old free (or paid) hex editor will do, so you don’t have to use notepad++ for this. I used HexEdit. http://www.physics.ohio-state.edu/~prewett/hexedit/
Close your sync if it’s running first. Run HexEdit, open GoogleCalendarSync.exe (after making a backup just to be safe), find row 2d580 (the 00, as in 002d580 above, is not shown in all editors) chage 75 to eb, save over your GoogleCalendarSync.exe, and it works!
Comment by j — July 3, 2010 @ 12:38 pm
not sure why you’d do the change yourself instead of just using the already-modified version I linked to, but that would work too.
BTW, I mentioned “There’s tons of hex editors out there” in the second part when I actually made a change to an exe (Outlook’s) – I didn’t actually make any changes in the first part, I just loaded it in the editor to show what byte was different as part of trying to show people that the modified one that had been posted just changed a conditional jump to an unconditional one
Comment by manningj — July 3, 2010 @ 2:43 pm
I also took the view that doing a single byte patch on a known .exe was safer than trying to do a compare on a downloaded file to see that the claimed difference really was the only change.
Call it normal paranoia!
Comment by Starnamer — July 3, 2010 @ 6:41 pm
BTW, great fix! Thanks.
(And why couldn’t someone at Google change the original so the check allowed 2010 anyway!?)
Comment by Starnamer — July 3, 2010 @ 6:43 pm
Just to be clear, I didn’t make either fix – just tried to add a bunch of verbosity to the work others had done
There’s a few possible reasons why Google hasn’t made this change themselves yet – the reality might be some mix of these or something different altogether, of course.
Comment by manningj — July 3, 2010 @ 8:05 pm
Works great with Windows 7 Ultimate, Outlook 2010 32-bit, GoogleCalendarSynch. Thanks.!
Comment by Steve Sachs — July 6, 2010 @ 4:32 pm
Win 7 64, Office 2010 32 bit, using modified google sync.
Is there anyway to adjust the sync frequency?
Thanks for the great work…
Comment by cb — July 8, 2010 @ 10:28 am
the sync frequency is part of the initial ‘settings’ dialog during install, which you can also access later via the systray icon’s context menu’s ‘options’.
See http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=89955
Comment by manningj — July 8, 2010 @ 12:09 pm
Thanks! If I knew there was a taskbar icon, I forgot about it…
Comment by cb — July 8, 2010 @ 2:20 pm
Strange — it was working fine yesterday, but today I get the message: “Could not initialize Google Calendar Sync Add-in for Microsoft Outlook: code 1011.”
Comment by cb — July 9, 2010 @ 11:14 am
Google Calendar Sync exe file method is the way to go. Worked great for Outlook 2010 32 bit on Windows 7. Simple fix – why won’t Google release a similar update? Many thanks.
Comment by Paul — July 10, 2010 @ 8:44 am
I cannot get the zip file to run (1st part)… any suggestions??? There is no unblock in properties either… I need my calendar. Thank you for all your hard work.
Comment by Tammy — July 12, 2010 @ 2:16 am
Windows XP Home SP3 – Office 2010 Pro Plus – Works great! I was weary of copying some random .exe file on to my system, but your succinct description of the .exe alteration allayed my fears and prompted me to take the chance… glad I did. Thanks!
Comment by seanohoulihan — July 14, 2010 @ 10:29 am
Thanks for the fix–you rock!
Comment by Dan — July 16, 2010 @ 6:16 pm
Hi
I have downloaded the hacked google file, but I can’t launch the app- nothing happens when I double-click-Any ideas/help would be greatly appreciated? Windows Vista – office 2010 32 bit
Comment by Suej — July 19, 2010 @ 7:59 am
you have to install the google calendar sync app first, and then afterwards you replace the .exe that it installs with the hacked one. If that’s what you did and it still won’t start, then I’m not sure what’s going on.
Glad to hear the hacked-outlook.exe approach worked for you, at least
Comment by manningj — July 19, 2010 @ 11:23 am
Not sure why the first solution, didn’t work – followed all the steps – (installing the sync and replacing the .exe file with the hacked). Really glad it’s working now with the second solution. Thank you for posting this and for giving a really well-explained and easy-to-follow work-around
Comment by suej — July 19, 2010 @ 1:39 pm
just an update: Tried the second solution – working great now
Comment by Suej — July 19, 2010 @ 9:34 am
Thank you . Works on Windows 7 / Outlook 2010.
Comment by Novice — July 19, 2010 @ 6:13 pm
Thanks! Works win7/outlook 2010 32 bit. Just what I was looking for.
Comment by Mike — July 26, 2010 @ 11:29 am
Fantastic, thank you very much, I do not now anything about computers or programming but I followed your instructions. Beautiful
Comment by Patrik from Norway — July 30, 2010 @ 7:28 am