Hit ctrl-alt-del to open Windows Task Manager (WTM). Under Processes tab,
scroll down to see System Idle Processes. Normally, it should be 99 (% ) or
close. If it's a much lower percentage, you should scroll up and see what
task (under taskmgr.exe or rundll) or service is using the balance of CPU
power (under CPU heading).
You can see the CPU usage on the bottom WTM bar after Processes, also.
Again, CPU Usage is the balance (to 100%) between System Idle Processes and
the sum of whatever else is running.
Then, right click on the task that is using most of your CPU, End Process...
and see what you get
Also, you can get the name of the service or of the
..exe file and find it on your computer so that you know what's doing there;
alternatively, you can google for that file name for details.
Michael