Hello and welcome to TSF
svchost.exe is a system process belonging to the Microsoft Windows Operating System which handles processes executed from DLLs. This program is important for the stable and secure running of your computer and should not be terminated.
Unless it could be a back door Trojan
Is your hard drive/s losing memory on it?
Have you found any files most likely illegal, on your system?
What secruity programs are you using?