NirSoft is a web site of over 250 free programs (only minor nags for donations) created by Nir Sofer. The software is mostly utility, maintenance, and diagnostic applications for Windows. Anyone who maintains a lot of computers, or likes to play around with computer systems beyond a cosmetic level, will find many useful programs on his site.
Some of the programs which I have found useful include:
I don't remember exactly which program it was that first drew me to NirSoft, but, once there, I was very impressed by the huge wealth of software on the site. I very much admire Sofer for all the hard work he has put into his programs and have found many of them to be very useful.