Windows XP contains a built in performance monitor that is constantly examining various areas of your system. This information can be called up using the performance monitor application found in control panel\administrative tools. Of course, most of us have little interest in this sort of performance statistics monitoring, that being more the territory of systems administrators than individual users.
To do this:
Go to the command prompt (‘start\run’ then type ‘cmd’) and type ‘diskperf -N’
Win XP comes with many inbuilt performance monitoring applications that constantly examine various parts of the system. This information can be of real use to a system administrator for collecting performance statistics. However, for a home user, these statistics hold no value and since the monitoring happens all the time, it consumes a good deal of system resources. “Disk monitoring”, for example, happens in the background, and turning it off is advisable if you will not be using the performance monitoring applications. To turn it off, type in “diskperf -N” at a command prompt. To bring up the command prompt: go to Start>Run, type in “cmd” and press [Enter].