This material first appeared at ghacks.net.
“The [linked article] describes how you can look up the disk reads and writes of any process on a computer running Microsoft Windows[, using Task Manager or Process Explorer].
It is probably a good idea to answer why someone would want information about disk read and write activity of processes first.
There are a couple of reasons. First, if you run a Solid State Drive, especially an early generation one, you may want to make sure that processes are not taxing the drive too much.
Another reason may be that you need to find out which process is responsible for lots of disk activity. Maybe because you can hear your drive thrashing around all the time, or because you notice slow downs when using the computer.”