Using Task Manager to identify a process that’s taking more than its fair share of CPU or memory resources is a start, but what happens when you can’t identify the specific process causing the problem? That’s likely to occur if a system service starts to spin out of control. In that case, you’ll see the excess resources attributed to a generic process (usually Svchost.exe), with no indication of which service is actually responsible.
Service Host (Svchost.exe) is a core piece of Windows XP code that collects a number of lower-level system-critical services and runs them in a common environment. By gathering multiple functions together, this arrangement reduces boot time and system overhead and eliminates the need to run dozens of separate low-level services.
Because different groups of services have different requirements in terms of system access and security, Windows XP creates a number of different groups. To see a list of which services are associated with each Svchost instance, click Start, click Run, type cmd in the Open box, and press Enter. In the Command Prompt window, type tasklist /svc /fi “imagename eq svchost.exe” (including the quotation marks).
(Note that the Tasklist command is only available with Windows XP Professional. If you have XP Home Edition, you can download the file from here.)
After you gather the names of services running in the context of a Svchost instance, you can do further research to see which one is causing your performance problem.
For more details on how to use the Tasklist command, type tasklist /? at a command prompt.