I already posted about PhraseExpress that I like a lot, but here are some more recommendations that I use on my Windows system:
Cobian Backup: Not the most beautiful user interface, but definitely the best free backup tool that I found and use on a daily basis. Has ALL the features.
JetDrive & PC Fresh: Two of our own programs that I use on my PC. JetDrive is the best defragmentation software on the market (in terms of PC speedup) and PC Fresh lets you configure all the low level stuff, that windows tries to hide from you. Both boost performance.
YouTube Song Downloader: Another one of our tools. Want to have music for free? We have the Windows tool. Getting YouTube avi videos or MP3 is no problem with this.
Skype: Why doesn’t everyone use Skype? It’s instant messaging with group conversations and included high quality phone service. It can send files. Perfect. (If the ads were removed.) You could even do video conferencing, but who would want that?
HeidiSQL: A free MySQL database client thats VERY nice and easy to use. If you find yourself or anyone else using phpmyadmin, tell that person that HeidiSQL is much better. Even if you need to tell it yourself.
TeamViewer: Help your father fix a Windows problem? Help a friend to setup his e-mail-client? Use this and share his screen and use your mouse and keyboard on his machine over the internet. Saves a lot of travelling time.
FileZilla: The best FTP client out there.
VLC: If you want to watch a video, just download this and watch it. Superb video player.
I’ll update this list if I find something else that I’d use every day.