Is svchost.exe a malware/virus or some kind of system file?
If you'd like to see what's running inside a particular svchost process, launch Task Manager and then add a column for PID. Make a note of the PID for the svchost process you're interested in. Now, launch a command prompt and type this, (minus the quotes of course)... "tasklist /svc"
Now match up the svchost PID's and you'll see what's running inside it. Have fun.
Yes Tina is correct and more specifically many processes and DLL's run within the SVCHost.exe process and it is common to have issues with the memory usage of this process. There are also applications like Process Explorer that let you see what SVChost is running. You can see more information on how to use it here http://www.bleepingcomputer.com/tutorials/tutorial129.html.
svchost.exe is a generic Windows system process needed to run .dll files. It's safe.
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