So many free utilities...
I am going to stick with the fix-it geek tools.
Profile Wizard - Allows you to join a computer to a domain and migrate the user's entire profile in 1-2 minutes. Invaluable for that one specific purpose.
SpySweeper - Though I am a fan of Spybot Search and Destroy and Adaware, I find that they do about 80% of the job on really screwed up computers. Spysweeper removes 98% of the spyware I have run into, but it is only free for the first use... so I typically clean the machine off with that, then install the free tools. Is that cheating?
Bart's Boot CD - Sometimes you just can't fix Windows in windows. This CD is part of my bag of tricks. Though it is not strictly "free" exactly...
FastPush Takes VNC to the next level allowing you to push it out to all the clients on your network. Everyone gets the same user account, password, settings. So sweet.
Panda Online Virus Scan - Often I want a second opinion in the evaluation of the virus situation on a computer. This tool allows me to scan the computer without installing any software. Symantec and Mcafee have this also but for some reason I like the Panda one better.
Belarc - Though I am sure this is on the Techsoup free tools. I really like Belarc for grabbing the inventory off a pc and presenting it in a good interface.
Alright that is enough.
Cheers,
Russ