Recently my computer suddenly became very slow. The SVCHOST service will start and consume some 80 to 100% of CPU and RAM shot up to 80K++
I made a temp fix by killing the SVCHOST process from Task Manager, which in turn stops my Workstation service. Not good. Survived for a few weeks. Until I sat down one evening to check it out.
SVCHOST is a service that is connecting to the network. One possibly it was corrupted by a virus eg Nimda or Spybot. I know is neither as my network interface is not blinking. Some forums suggested using Sysinternals (now a Microsoft company) Process Explorer.
I installed it and guess who is using SVCHOST?
Automatic Updates. I had 15 updates downloaded and waiting for me to install but I never did.
Morale of the story, if you don't patch the computer, Automatic Updates will force you. Otherwise turn it off