Venmon - Compact size system resources monitoring utility and multi-ping tool for Windows
Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
Taskbar Meters - Incredibly simple meters that live in the Windows 7 task bar.
SpeedFan - Hardware monitor for Windows that can access digital temperature sensors located on several 2-wire SMBus Serial Bus. Can access voltages and fan speeds and control fan speeds. Includes technical articles and docs.
Mousotron - Mousotron is a mouse and keyboard activity monitor and keeps statistics of your mileage. It's like an odometer or tripometer for your mouse cursor.
Core Temp - Nov 4, 2017 - Core Temp is a compact, no fuss, small footprint, yet powerful program to monitor processor temperature and other vital information.