My CPU Monitor is a small, lightweight tool that accurately keeps track of cpu usage in real time - right from the systray. The tool uses two simple icons, one shows percentage meter and the other provides a processor load graph. It allows you to choose at what predetermined level a high usage warning is displayed. You have 2 choices of warning type; you can have the icon blink or show a warning message. This is not a fancy tool, but it does the job and keeps you informed.
CrystalDiskInfo is an Open Source utility that monitors and displays the health of your hard drive, including basic information, S.M.A.R.T. values, and disk temperature. Also available as a portable version.
PRTG - Free Network Monitor is a network monitoring solution that ensures the availability of network components while also measuring traffic and usage.
CrystalDiskInfo Portable is an Open Source utility that monitors and displays the health of your hard drive, including basic information, S.M.A.R.T. values, and disk temperature. Also available as an installer.
Wireless Network Watcher is a small freeware monitoring tool that quickly scans your wireless network and then lists all the computers and devices that are currently connected.