HDD Led Indicator - This is a hard disk activity monitoring tool.
CPU-Z - CPU-Z is a freeware that gathers information on some of the main devices of your system : Processor name and number, codename, process, package, cache levels.
Atlas Hard Drive LED - Atlas Hard Drive LED is a system tray utility program that allows the user to always be aware of whether their hard drive is reading or writing. The system tray icon will change to the color red when the selected hard drive is processing.
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.
DiskLED - DiskLED is a flexible hard disk and general system activity indicator system tray applet.
AIDA64 - AIDA64 is a system information, diagnostics and benchmarking solution for Windows PC.