I’ve been running the 64 bit and 32 bit betas of Windows 7 on a few machines and for the first few hours I was very happy on all of them as the beta has been at least as stable as Vista has been.
However, without exception, all 3 machines started crashing whenever I tried running any installation program that uses Microsoft’s MSI installer. This meant I couldn’t install some of my most used applications, including a key one for work, the VMWare Virtual Infrastructure client.
This got so frustrating that I was on the verge of binning the beta until a last ditch Google search uncovered this is a widespread issue affecting the beta that has a relatively simple fix.
A detailed page on the problem can be found here: http://www.neowin.net/news/main/09/01/19/windows-7-beta-testers-find-critical-windows-installer-bug
I have no evidence on the cause of this but my hunch is either Adobe Acrobat or Adobe Air installers as all seemed to be well and these were the first apps on all machines to exhibit the issue and then every MSI install failed after that.
The fix that worked for me was deleting all keys apart from "Default” in HKLM\Software\Microsoft\SQMClient\Windows\DisabledSessions using REGEDIT.
Update apparently Microsoft have updated the Crash Reporter with feedback when this bug gets reported to Microsoft.