I just bought MacBook Pro + Parallels last week. Installed XP with Servie Pack 2. Then upgraded to SP3. Seemed to work fine. Then installed MS Office 2007 and a couple more Windows upgrades and now my entire virtual machine fails to boot up. It hangs every time I attempt to start up. Not only that, it just about freezes the entire Mac OS too: seems like it's occupying so much processor capacity that I can't do anything on the Mac side -- takes several minutes just to get Parallels to close. Anyone else experience this? Can anyone help?
You can try to repair windows XP installation. Parallels has KB article =) http://kb.parallels.com/en/5138