I bought recently an XBox 360 PC controller, and was thinking about getting a second one. Can I simply buy a controller that isn't labeled for PC (and doesn't has the adapter) which is cheaper and then pair it with my already existing adapter? The adapter in theory supports up to 4 controllers, however I like to make sure before I buy something :).

[Removed answer about wired controllers]

EDIT: Wait, you're talking about wireless controllers. Sorry, I don't know whether a single adapter can be paired to multiple controllers simultaneously. Beyond that, yes, it'll work.

Yeah a single wireless adapter can connect with up to 4 controllers simultaneously. My sons and I do it all the time. Haven't tried more than that but I assume since the wireless adapter only sets up four joysticks it can only handle four.

EDIT:
Oh and all my controllers have been ones I've picked up from xbox users. None were labelled for windows.

Also, the only thing that makes it bear the "PC" marking is the inclusion of the wireless adapter in the package. Ignoring that, all controllers are the same.

Cool,thanks for the replies. Now looking forward to Black Suckerday (here many retailers raised prices in the last couple of weeks in anticipation of "Black Friday"), maybe i see some deal.