Faulting application w3wp.exe, version 6.0.3790.1830, stamp 42435be1, faulting module stswel.dll, version 11.0.6568.0, stamp 42e17544, debug? 0, fault address 0x0009310c.

This is something I fell victim about 18 months ago, pre-SP1 for Windows SharePoint Services, and I'd forgotten about until the recent release of SP2 for both WSS and SPS. By the time I had resolved the problem and discussed it with the Microsoft Escalation Engineer we had standing by, SP1 was already in testing. It was said that a "fix" may not make that service pack. So, it was worked around and was duly forgotten until now -- the release of SP2 -- and so I decided to see if it had been "fixed."

Error 1928. error registering COM+ application. Contact your support personnel for more information.
orError 5003. Regsvcs failed for assembly c:\program files\Microsoft Biztalk Server 2004\Microsoft.Biztalk.Deployment.dll. Return code 1. (BizTalk SP1)

I ran into the above error while installing BizTalk 2004 dev/sdk components onto my windows xp/sp2 box and spent a few hours debugging the problem and managed to find a workaround. The problem stems from overly tight default permissions on keys created under HKLM\software\classes during the install.