PsTools from Sysinternals is a collection of command line utilities that let you manipulate processes in Windows. Among the tools, I personally use pslist and pskill every single day(*). Check it out!
And if you have pslist, then put the following into a batch file, say mlist.bat. It’s very handy for nailing down memory leaks. (Note that the @ sign in the front of a command in a batch file suppresses the echoing of the command. That’s why many batch files start with @echo off.)
@pslist | sort -n +5 | tail -n 10
BTW, with the release of Windows XP and Windows Server 2003, Microsoft has bundled two command line tools that do similar things (tasklist and taskkill). However, their command line interface is awkward. I recommend you forget about them and stick with PsTools.
(*) largely because of Firefox and Acrobat