You'll see this same type of error all over this newsgroup. You didn't
explain much, so I'll throw out some tips I used to get RC1 up and installed.
First, it is highly advisable to install this in a dual-boot setup (i.e. XP
on C:, and create a new partition called Vista wherever). Create that Vista
partition to be => 35GB (preferably => 40 GB). Mine installed okay on 29GB.
Do NOT install from the DVD (i.e. leaving it in the drive and re-booting).
Doing that, and you could lose your drive letter settings, and possibly XP
itself! Boot into XP, eject the Vista DVD, and put it back in the drive.
Now autorun should pick up the install. Choose "custom" install when asked.
Choose the Vista partition as your drive of choice. Enter your key, and walk
away (really - you'll go nuts staring at a screen for an hour). Providing
your DVD is a good burn, all should go well from here on out. After several
re-boots, and LONG delays, you should get a boot menu. RC1 looks great, and
runs fast (esp. Internet). Still gotta work out the UAC prompts (but UAC is
noticeably better). Good luck!