Services You Can Disable in Windows Vista

There are several services you can disable to help improve performance.

Desktop Window Manager Session Manager - Provides Desktop Window Manager startup and maintenance services.
If you don't plan on using Aero Glass, you can disable this service.

Diagnostic Policy Service - Enables problem detection, troubleshooting and resolution for Windows components
Set to Disabled

Diagnostic Service Host - Same as above

Diagnostic System Host - Same as above

Offline Files - The Offline Files service performs maintenance activities on the Offline Files cache, responds to user logon and logoff events, implements the internals of the public API, and dispatches interesting events to those interested in Offline Files activities and changes in cache state.

Terminal Services - Allows users to connect interactively to a remote computer. Remote Desktop and Terminal Server depend on this service. If you don't use either of these, then you can disable the service.

Windows Error Reporting Service - Allows errors to be reported when programs stop working or responding and allows existing solutions to be delivered.

Windows Search - Formerly this was the Indexing Service. Provides content indexing.