To use a wireless controller with Windows note that you will need a receiver; the 360-branded wireless bundle includes one, but otherwise you will need to track down a separate one (such as this one). The Play & Charge cable will not work because it only carries power. BlueTooth receivers are also not compatible (PS3 and Wii controllers can be used via BlueTooth, however).

Windows should detect the controller and download the drivers for you, but you can also download them manually from this page ("Xbox 360 Accessories Software"). Windows-branded controller bundles include the drivers on a CD, but the version on the website is newer than the one that came with mine so check there first regardless.

Legacy games will usually work fine with the 360 controller--although some can't see the triggers because they are axes, not buttons--but note that the central "Guide" button can't be mapped in any game (this is not an error on your end).

One useful bonus of the 360 controller is that Windows can see headsets plugged into it (even generic ones--anything that fits the jack), and it will show up as additional input and output devices just like a headset connected directly would. I'm not sure whether the Messenger Keyboard is supported though. x360ce makes legacy controllers show up as 360 controllers. It isn't perfect yet, and of course games can only see as many buttons as a 360 controller actually has, but you should definitely give this a try before investing in a new controller, especially if you are otherwise happy with your existing controllers.

Official Nintendo hardware tends to be quite sturdy (ie. made for kids a throwing temper tantrum), so it's not that surprising if he has a SNES controller that still works. I got 2 3rd party 360 controllers for less than the price of one Microsoft one, they've been working flawlessly so far.

The problem is that the official Xbox360 controller uses XInput while almost every other controller there (be it for the XBox or PC) uses DirectInput; this means that if the developers chose to only support the Xbox360 controller they'll only code against XInput and not DirectInput which means that the rest of the controllers will either not work or work badly.

This happened recently with Super Meat Boy: the initial PC version only had XInput support and other controllers didn't work, but it was later patched with DirectInput support.