XMeters is a well-designed system monitor which displays live CPU, RAM, network and drive stats directly on your taskbar.
A bar graph displays CPU utilisation by core; there are figures detailing hard drive read/ write rates, and network upload/ rates; and a pie chart updates to show free and used RAM.
Right-clicking any of the monitors opens a configuration dialog. You can reorder any of these items, turn them on or off individually, change their display type (bar, pie or text), set colours and more.
Left-clicking a monitor opens task manager, handy if you need to explore your PC further.
XMeters is free for personal use. A $4.99 Professional build can be used by everyone, and extends the package with a fully configurable refresh rate.
System monitors aren't the most essential of apps as Windows now displays plenty of details all on its own. XMeters ability to display its details on the taskbar is unusual, though, and if that appeals, give it a try.