Tools for Troubleshooting: Windows Sysinternals
Recall, Microsoft acquired Sysinternals in July, 2006. I was a big fan of Sysinternal's toolset and the good news it is still getting better. If you're an admin or developer, these tools will help you manage, troubleshoot and diagnose problems.
I currently use Process Explorer, Handle, BgInfo and Zoomit. Go check things out.