Microsoft Process Explorer

Windows Process Explorer (download here) is an excellent utility to see information about what processes have a hold of files on your machine. It's most useful when you get strange errors with files, or are unable to save, edit, open or otherwise act on a file or folder.

When my computer is freezing up or even running slower than I think it should, my first instinct is usually to open task manager (hit CTL+ALT+DEL) and sort processes by memory usage, then start using the "End Process" button like the trigger on my XBox controller. The problem with this approach is not knowing exactly which processes I am stopping, more importantly, how to fix it through the next reboot.

I like the Process Explorer Utility because it allows you to take the opposite approach by finding the file or application that's giving you trouble, then locating which service has the lock on it. You can then go in much more surgically to the single source of the problem and stop it directly.

Additionally, when you can identify a service that is both problematic and unneccessary, you can go in to your Services Window (Control Panel > Administrative Tools > Services) and disable them by choosing either "Manual" or "Disabled" status.

Here's the link to Microsoft's site where you can read more or download the program:

http://www.microsoft.com/technet/sysinternals/utilities/processexplorer.mspx

Enjoy!