I use this and like it. Gizmo from Techsupport gave it a nice review.

"For many years the SysInternals crew has offered the best product in this category. Unfortunately, the last couple of years has brought some great free, open source, projects that are very deserving contenders for the top spot.

This application was referred by a site visitor and was new to me, although it has been around a couple of years. It did not take me long to appreciate all that this program has to offer, and I was pleasantly surprised by how easy it is to use. System Explorer has some truly useful features available, such as the ability to take and compare snapshots of your files and registry, to upload files to Virustotal, and to perform an online look up of files or processes straight from the GUI. This handy process viewer also gives you mouse over information on known files, as well as many options to further manipulate processes, files, and services. Everything you need to get to is organized in a left hand column and you can view everything from your services and processes, Internet Explorer Add-ons, to protocol filters and handlers for Windows Explorer. I admit a lot of this stuff you might not use very much and some software can get kind of bloated when there are this many features but it is no problem here, and everything fits together very nicely. In my opinion, System Explorer is absolutely the best free process viewer available even if it is missing a few of the more advanced features."

Available as an installer or portable (my choice). Free for personal or commercial use.

http://www.systemexplorer.net/index.php