Once eSignal is running it does not normally use the hard drive. It would in cases where you do not have a lot of amount of RAM (Random Access Memory) or a pretty slow process on the computer. Windows creates a larger Page File to compensate for the lack of physical memory. Since the Page File uses the hard drive to swap data between RAM and the hard drive you would hear the hard drive working. I would guess that you would also have a couple of other high intensity applications running as well. AveryH