Microsoft recently updated the Customer Experience Improvement Program Client that is included on all Windows 7 betas. Some of the new settings are known to cause application installs to crash.
CEIP is a great tool that allows Microsoft to see what drivers they are missing and what programs are crashing on your computer. However, with the recent settings change it was causing more problems than solving.
To help beta users Microsoft provided a simple command line hack that will fix the CEIP client. Just open up an administrator level command prompt (right click on command prompt in the start menu and select Run as Administrator) and type in:
reg delete HKLM\SOFTWARE\Microsoft\SQMClient\Windows\DisabledSessions /va /f
Once you run the command close the command prompt window and you are ready to install application again.