Vista - Unsuccessful upgrade from XP to RC2

Tried to use RC2 to upgrade my XP. computer is pretty generic DELL XPS
although fairly powerful with 2 GB of RAM. Probably the most nonstandard
thing is that I have IE7 RC1 installed. I launched RC2 from XP and it
found about 5 programs it said would not work after the upgrade. That was
ok with me. The upgrade ran overnight and in the morning I found a message
like "VC++ crashed"... I didn't realize it was a fatal error so I hit ok
without writing down the message. It then proceeded to rollback to XP. It
did this successfully. This computer has successfully run Beta 2 and RC2
with a clean installation.

Unfortunately when I reported the bug using the tool, it asked me about
debug log files that must have been lost during the rollback to XP.

Of course, I was just curious what the upgrade would do. For my real world
machine, I use clean installs.

Knox