HWiNFO are professional hardware information and diagnostic tools supporting latest components, industry technologies and standards. Both tools are designed to collect and present the maximum amount of information possible about computers hardware which makes them suitable for...
The Open Hardware Monitor is a free open source software that monitors temperature sensors, fan speeds, voltages, load and clock speeds of a computer.
There has not been any code change since December 2020, also the community now wonders if it is abandoned: https://github.com/openhardwaremonitor/openhardwaremonitor/issues/1471 There also seems to be a fork called LibreHardwareMonitor (which is already listed as an alternative) and appears to be the most active fork right now.
A powerful overclocking tool for your graphics card, which also includes screen capture and video capture tools, plus overlays. Has a lower FPS hit than Fraps, and offers the same functionality. The beta versions include audio streams alongside the video capture.
SidebarDiagnostics - A simple sidebar for Windows desktop that displays hardware diagnostic information.
SpeedFan is a program that monitors voltages, fan speeds and temperatures in computers with hardware monitor chips. SpeedFan can even access S.M.A.R.T. info and show hard disk temperatures. SpeedFan supports SCSI disks too.Discontinued
The developer promised new versions, but the program seems to be no longer updated. Latest version, 4.52, released in June 2016, can be still downloaded from the official website.
iStat is a series of system monitor apps. It's available in different versions: iStat Menus, iStat for iOS and iStat Server as a companion application to the iStat for iOS app that lets you remotely monitor your computers (free for Windows and Mac).
Core Temp is a compact, no fuss, small footprint, yet powerful program to monitor processor temperature and other vital information.Bundleware
The installation may contain adwares. Be careful during the installation: https://alternativeto.net/discussions/applications/11718/be-careful-in-the-installation/