I have a wireless Xbox 360 controller with its USB charger. Can I use it as a wired controller to play on my PC without buying the wireless receiver for Windows?
And if so, where can I find the drivers for Windows 7 64-bit (if available)?
There is no way. Microsoft made it so the Play and Charge Kit only receives power. I believe there is some other data that is sent to the controller as well that someone decoded but there is no data sent to the computer from the controller. I will try to dig up a link.
On the other hand, you could just buy a wired controller, those are about as expensive as the wireless receiver, work on both PC and Xbox/Xbox360, and you'd have an extra controller for a friend.
It is possible, if you have an old junked xbox, you can rig it up with the 360 RF receiver and an old USB cable that you don't mind cutting up. after that a small change to the INF file for the drivers your all set using your wireless 360 controller on your pc. Also on a side note, when I first attempted this I didn't compensate for voltage and ended up seriously damaging the usb controller, so don't attempt unless you know a bit about it. Not going to post a how to tutorial here but, you can find near anything on the net. =]