Are you unable to install programs on your Windows 7 beta? You're probably a victim of this MSI installer bug, which you can actually fix by yourself, right now, without waiting for a Microsoft patch.
Here's what you do.
1. Open a Command Prompt as Administrator
reg delete HKLM\SOFTWARE\Microsoft\SQMClient\Windows\DisabledSessions /va /fand press enter.
That's it. To open command prompt as an admin, you'll have to set the User Account Control slider to the lowest setting (Never notify), then reboot.