Vista - Lost data files and favorites in Vista Beta 2

I upgraded my XP Pro machine to Windows Vista beta 2. It ran well for about 1
week and I attempted to install Symantec Antivirus 10.2 for Vista. It
installed fine and initially ran fine but when I rebooted all I got was blue
screens.

I performed a System Restore and the system booted fine but then I found
that all of my documents in the "My Documents" folder and on my desktop were
gone. The folders/directories were still there, however. It also appears
that any binaries were untouched, only MS Office document types were deleted.
In addition, I lost my Firefox bookmarks and my IE7 favorites.

Using a program called Restoration I was able to find all of my files -
which apparently were deleted. I was able to restore them but some of them
are now corrupt.

I don't know how this could happen.....

And, is it at all possible to now upgrade to Vista Enterprise without
performing a complete reinstallation?

Thanks for any explanation/advice.

Steve H.
(former MCSE from years ago)