Rainmeter is a lightweight Open Source software for quickly displaying important system information. It's intended to help you stay on top of your system resources and more.
Rainmeter provides customizable data views (via skins), referencing your allocated memory, CPU load, network traffic, performance data, free disk space, uptime, online data streams, including email, RSS feeds, and weather forecasts. Having all that data at your fingertips will make it the go-to utility for helping keep your PC running in tip-top shape. It provides you with upfront information about which resources may be causing your machine to lag. The benefit of having multiple resource meters available is that you can close any offending apps down immediately.
It can also keep you informed on your available partition space enabling you to clean up accumulated redundant or obsolete files and folders before a potential issue arises.