the charge and play cable is only for charging the controller, does not allow for USB control on the PC.
I see quite a few people hook it up that way not realizing that it won't work.
Do you have this Wireless adapter? Amazon.com: Xbox 360 Wireless Gaming Receiver for Windows: Video Games: Reviews, Prices & more
btw, I plugged in my receiver and Win 7 recognized it and installed the drivers
automatically, then I synced my controller and played Just Cause 2 for a few hours last week.
If you have the off-brand Chinese 360 Adapter then there are some steps you have to do to get it to install in Win 7 properly.
there was a thread here a week or two ago about other adapter, I'll see if I can find it.