Question: My windows (XP) hard drive grinds a lot and it negatively affects the performance of other applications.

I have plenty of RAM and have already verified that this hard drive activity is not page file swap activity. ?I have also already looked in task manager to see if only one or two processes are active but I have found no smoking gun.

What tools can I use to directly determine what application or feature of the OS is causing the hard drive activity?

Answer: Process Explorer. ?Make sure you show the columns that contain the I/O activity.

Sometimes you may see a process running multiple services that causes the activity. ?In that case, it requires a bit of guesswork.