This is the Services panel within Windows which can be found by going to the Control Panel, opening Administrative Tools and then Services. Here you can Stop, Start, Enable and Disable services that you may not be using that will and can hinder your performance of the operating system.

By double clicking on a service you enter the properties page for that specific service. Obviously it is best to not change any services until you are fully aware of what services you can or can not change the status of. Certain services that are stopped or disabled may increase the chance that will cause Windows to not work properly! Within the properties of the service you can set the startup type to Automatic, Manual or Disabled.