**HERE'S THE REST (sorry, I accidentally hit the SUBMIT-Reply button) **
I had a similar problem upgrading my OS from XP Home to XP-professional
(I use Dutch version,so there can be slight difference in terminology)
Installation failed G:\i386\asms DATA error (cyclic redundancy control)
After reboot, I was able to continue set-up in Repair-mode, and used a fresh copy of XP-pro. The rest of the install-process was without problems, and I didn't experience troubles, until...
I tried copying the main-profile.local (that I had been using in XP-home) to a network profile with a similar name "main-profile.network" My pc got stuck an displayed the FATAL ERROR-SCREEN (twice) and afterwards I wasn't even offered the Profile-COPY to-option in My Computer/properties/user profiles any more...(greyed out)
(of course the Copy to-function can be retrieved through system-restore: I get the same Fatal Error screen twice again and then it greys out again)
SECOND PROBLEM is that when trying to use Remote Desktop Control from another machine to the "Main Profile.local" on my pc, it's access is denied: "cannot sign on because of account restriction" (translated from Dutch)
Maybe my problem is caused by Outlook Express. In XP home, I had two identities: 'Main' Identity an 'Private'-Identity, both of which I couldn't remember the Identity-password of. As long as nothing changed, when activating OE it started up in this new created ('Private') Identity and there was no problem.
But after running Service Pack 2, still in XP-home edition, OE persisted on starting up Main Identity, asked me for its Identity password (which I don't remember) The only way to read emails in OE was to undo SP2 by SystemRestore.
Fortunately upgrading to XPpro/SP1 didn't bring on the same problem; even after running SP2 (this time in XPpro) activating OE in Main-profile.local starts up my "Private"Identity without asking for Identity passwords; and I can read my mail.
I told you about my problems with copying this profile to a network profile, so I tried, while logging in as administrator, a manual copying-procedure (copy /paste) of C:\documents and settings\main-profile.local -> c:\documents and settings\main-profile.network
This seemed to work well, it acts like an identical copy of main-profile.local, it
even allows unrestricted access by Remote Desktop Control,
BUT: Outlook Express will NOT PERMIT ME TO READ MY MAIL !! (

)
It opens Private-Identity all right, does NOT ask for my OE-Identity password, only asks for my internet-provider password, than receives new messages, but when trying opening a message it reads:
ERROR in Outlook Express (or something of the kind)
DOES ANYONE HAVE ANY IDEAS ABOUT THIS ??
SHOULD I RETRY upgrade XPpro (SP2 this time) ??
or Like ULTRASOLVE suggested: run a separate install of i386 from c :\windows\i386 (after copying it from my CD XPpro/SP2 this time)
(PS: could anyone instruct me how to do this, a separate install ?)