Windows 7: Keyboard doesnt work anymore!

I was unplugging my usb receiver for my usb keyboard and mouse, to and plugged it into a diffrent port when i notice popped up say that the usb driver was not installed correctly. Then another notice popped up saying that my internet was disconnected. (I have a usb router.) My mouse and keyboard didn't work now. I thought this was a fluke and restarted my computer.

Now and i cannot log-on. This happened a couple hours after installed Windows 7. I can however use the keyboard when the computer just boots up but not at the login screen.

Any solutions?

Is there a reset button on the receiver?

Yeah there is. Like small red button. I've tried that too.
Like I've said the keyboard works in boot screen but not at the log in screen.