AppReadWriteCounter – Find out which programs are furiously reading/writing your disk

AppReadWriteCounter is a very simple but practical hard disk read and write monitoring tool developed by NirSoft. With it, you can quickly see the detail info about every application in your system that is reading and writing to the hard drive, and monitor that information in real time, so that any changes can be displayed in time. Like other NirSoft tools, it's free, tiny, portable, and very easy to use.