In keeping with the holiday spirit-o-giving, and so that I'm not completely idle, I have a slew of freebie recommendations. These are little free things that Windows should've come with, and I use 'em a lot. They're all reasonably small and very useful. Hopefully you'll end up using 'em as much as I do.
Associations: A gizmo that lets you set or reset file associations, so you don't have to use the registry editor.
Startup Manager: Shows you all the stuff that runs when the system starts up, and allows you to enable, disable, add, or delete 'em. Top notch.
Programmer's File Editor: My favorite Notepad replacement. Very fast, loads files of unlimited size, and has excellent search-n-replace.
Frhed: Free Hex Editor. Binary-only companion to PFE.
Password Corral: A very simple database that keeps track of your passwords. I use this all the time.
WinAmp: Provided that you ignore all the kEwL sKiNz and pointless add-ons that are bogging down this product, this is a terrific audio player for Windows.
XCalc: An excellent replacement for the crusty old Windows calculator. I've got an old HP I use most of the time, but this is a good backup when the HP is too buried to find.
Chmap: Replacement for the Character Map applet that comes with Windows. Small, free, and better than the one that comes with Windows.
InfoZip Zip/Unzip: Command-line zip and unzip tools for every platform out there. As good as the commercial ones and 102% free.
ZipCentral: A clone of commercial GUI zip-tools. Absolutely free and very easy to use. As an added bonus, it can make self-exploding archives.
AnalogX POW: Little critter that sits in your system tray and kills browser ad windows. There are lots of utilities like this one out there, but this one is really small and hasn't yet accidentally killed a window that I wanted to read --something I can't say about the other products.
Magic Mail Monitor: Another useful tool if you have a full-time internet connection. It sits in your system tray and shows if you have any new email from one or more accounts. If you have mail, you can pop it up and see who the mail's from. Only complaint is that it gets unstable if your connection goes down. It doesn't cause trouble for anything but itself, though, so it still stays on my list.
CmdTime: About the simplest internet time-synchronizer I've found. Just type CmdTime /q, and it'll sync up your clock. Can't get much simpler than that. My computer's clock is pretty accurate, so I only run this thing about once every six months or so.