Someone on the MSSMS list recently had a situation in which a svchost.exe process was hanging. Since most systems will have multiple svchost processes running, it's helpful to be able to determine what's the cause of the problem.

On WinXP:

tasklist /svc | find "svchost"

will output the process name (svchost.exe), the PID, and the associated Windows services that are running in each. Sometimes they double-up, but it at least helps narrow it down a bit.

This command isn't present in Win2k, but I wouldn't be surprised if SysInternals or the Windows Resource Kit has a similar tool.