missing or corrupt files 70241 (very common) usually means a bad Vista download - one that prematurely stopped, or was interupted.
The good news is that there are MD5 checksums for all Beta's, checkable with Nero MD5 verifier.exe utility from their website.
I would never think of trying a Vista install without a MD5 or CRC check.
The bad news is that there is no checksum info for 5552 yet:
http://board.iexbeta.com/index.php?showtopic=23258
As far as "upgrading" a current XP install - is definitely not a good idea.
Remember there have been betas, beta 1's, beta 2's, in house beta's, leaked beta's, official beta's MDSN subscriber and SDK beta's, and an in house that went public beta (5552). (MS is deperate to unviel an O/S that works, since it is now over 2 years overdue, the EU fines, and Linux biting at its heels. Recall thet Gates totally reshuffled the Vista team a while back in disgust.)
There is a validation process for Vista upgrade during install, but this was or was not working/working properly depending on the beta. There are also issues as to whether OEM or Retail or VLK XP installations/CD's/keys will be allowed etc. For sure Vista Retail will be XP SP2 upgradeable on Jan 07
Best option:
Install to vmware (VirtPC) on separate partition - easily removable
(Note: Vista requires 7.5GB MINUMUM Partition 15GB recommended)
second best:
Clean hardrive, one big partition, fresh install Vista, primary active partition
http://www.lifehacker.com/software/top/...indows-xp-and-windows-vista-179906.php
third option:
XP Pro SP2 on HDD0, prim active, Vista on HDD1 primary active.
Fourth best option:
XP Pro SP2, on C primary active
Vista on D, dual boot. Vista bootpro to uninstall
http://www.pro-networks.org/vistabootpro/