In Vista, you can now view which processes are running under instances of
svchost.exe by using Task Manager. It doesn't show as much detail as the
tools Kerry mentions below, but it's also built-in to Vista.
To view which services are currently running under svchost.exe
1. Open Task Manager by right-clicking the taskbar and then clicking Task
Manager.
2. Click the Processes tab.
3. Click Show processes from all users. If you are prompted for an
administrator password or confirmation, type the password or provide
confirmation.
4. Right-click an instance of svchost.exe, and then click Go to Service(s).
The services associated with the process are highlighted on the Services
tab.
More info at Windows Help and How-to online at
http://windowshelp.microsoft.com/Windows/en-US/Help/057580a1-7002-4f43-9240-a74f42cb05c91033.mspx#EV