DCOM and ASP.NET error and warning after SharePoint installation

In case you get the DCOM error logged to the windows events after installing SharePoint (MOSS), go to the IWAN Reg Admin Service reacheable from the administrative Tools -> Component services and grant the accounts (application Pool accounts) specified in the event error, launch permissions.

If you have the ASP.NET warning and do not reach your SSP admin site, add the following Windows accounts and permissions to the Windows\temp folder:
IISwpg Read and Network service modify permissions.

If you still have a problem, follow KB 825791.