Anyone who’s opened the task manager in any version of Windows has seen the process “svchost.exe” at one point or another. What’s more confusing is that svchost is usually found to have more than one instance!
What are they all doing there, and just how much of my precious memory are they wasting?
Svchost is kind of a catch-all. It is used to host multiple services within one process. This helps to actually conserve memory in your system by having one process govern many. Stuff like Windows Update, the Event Log, Audio Services and bunches of other programs, processes and the like can be found under the svchost umbrella.
If you want to identify what services are using svchost, do this:
In Windows Vista and 7:
Just open task manager (Ctrl+Shift+Esc), click on the “processes” tab and click “Show processes from all users” at the bottom. Note: there may be a User Account Control Window or you may need to be logged in as an Administrator. Next, Right-Click on any of the svchost processes and select “Go to Services”. There they are, every item that uses a process which you now know more about!