The Hard Disk Activity Notifier fulfills your need to check the status of what your hard drive is up to. It used to be that you could either see your hard drive LED or hear the drive heads reading and writing to know if you did indeed double click that icon on your desktop. With solid state drives, there is nothing to hear, and with some laptops and tablets, there is no disk drive LED. I found myself in that position with a new machine and decided to do something about it.
This simple utility runs in the Windows notification tray and -very subtlety- blinks when your disk is read (top indicator) and/or written (bottom) to. It matches the other white Windows icons so it does not look out of place.