CPU usage keep going up and down even when computer is not use.

[Guest]

My CPU usage keep going up from 1% through 36%, 46%, 50% randomly and then
goes back to 1% again. CPU usage keep going up and down this seem to happen
when i hear my harddrive make a whistling sound. I disable my antivirus and
still does that and it also happen when computer is not being use.

Is this CPU usage activity normal in Window Vista?

 

[R. McCarty]

Most likely it's background or idle time tasks. Vista has a number of
maintenance type scheduled tasks. Some work from a fixed schedule
and others are triggered. Some will run when the system has been at
an idle state for a period of time.
Best to use a tool, such as SysInternals Process Explorer. It can give
you very exact information on what process(es) are running the system
resources used by them.

Download and tool description here:
http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/ProcessExplorer.mspx

 

[Guest]

Same problem as GT. The program "searchprotocolhost.exe" reads my harddisk
all the time. Is this normal?