I downloaded and installed the Office 2010 technical preview today. All seemed to go OK (after I realised I could only do an in place upgrade from 32bit Office 2007 –> 32bit Office 2010), once the upgrade was done I could load Word and using our VSTO based document templates all seemed to work fine. However when I tried Outlook I got a problem.
On the first loading it took a while, telling me it was doing something to 40K+ items, presumably checking the local OST file, but then seemed to load OK. However after about 30 seconds it crashed, and continued to do this every time I rebooted Outlook even when I was tried safe mode, add-ins switched off and/or offline working. It all had no effect. Checking the event log I saw I had the error:
Faulting application name: OUTLOOK.EXE, version: 14.0.4006.1110, time stamp: 0x4a468538
Faulting module name: mlang.dll, version: 6.1.7100.0, time stamp: 0x49eea59f
Exception code: 0xc0000005
Fault offset: 0x00016aef
Faulting process id: 0x1060
Faulting application start time: 0x01ca06e3140fb30d
Faulting application path: C:\Program Files (x86)\Microsoft Office\Office14\OUTLOOK.EXE
Faulting module path: C:\Windows\system32\mlang.dll
Report Id: 5af5a171-72d6-11de-97df-001636a51764
I noticed that the in place upgrade had not removed Office 2007, so I did this via the control panel. After this Outlook loaded and was stable other than the fact the view panel would not load (was grey’d out on the menu), so stable but useless
I then tried a removing Office 2010 (there is no repair option) and reinstalling again using the same 32bit media. This time it knew it was not doing an upgrade but a new install. Once this completed I loaded Outlook and it worked fine including picking up my existing OST file (from a non default location, I keep it on a bitlocker partition) and also still had my CRM 4.0 add-in configured and working.
So it seems the upgrade can get bit confused