Process Explorer

Free Download

Ever wonder what's causing your computer to hang? You can fire up the standard Windows Task Manager and see what process are using CPU and RAM, or you can run this free tool from Mark Russinovich (and later purchased by Microsoft) and learn much, much more about what your computer is doing.
A two-pane view breaks down processes and their corresponding components and DLLs, and the data columns are sortable and customizable. Kill multiple processes simultaneously or right-click to see more info about any process, including all of the related Windows Services.

If you've ever tried tracking down a process in Windows Task Manager, you know it's like looking for a needle in a haystack. Process Explorer makes the job a lot easier. This freeware utility displays running processes in an intuitive tree format that includes not only process names, but also program icons and other data, such as description, image, and processor time.
It also can identify the process for a given application window or look up a process name in Google--a handy way to spot spyware. The latest version, more than three years in the making, introduces several new features. You can now drill down into the multiple svchost processes and see what each one is controlling via mouse-over tooltip, learn which Internet Explorer 8 process controls which tab, and a new .NET assembly information tab under Properties for assistance in .NET troubleshooting.
Additional features offer detailed information on performance, DLLs, threads, handles, TCP/IP connections, security settings, and environments. Despite its lack of visual polish, Process Explorer is one of the best Task Manager replacements we've seen.