I kept getting the error: "Error while trying to run project: Unable to start debugging on the web server. The COM+ registry database detected a system error". I wasn't finding a solution with the associated help file.
Finally I installed the .Net 1.1 Service Pack 1, and that fixed it.
I also heard that running %WINDOWS%\system32\secedit.exe would fix the registry problem, but I have not personally tried it.