Click the Start button , click Control Panel, click Hardware and Sound, and then click Bluetooth Devices.
Select the keyboard or mouse that's not working, and then click Remove.
Click Add, press the reset button on the bottom of the keyboard or mouse, select the My device is set up and ready to be found check box, and then click Next.
If the device is not found, repeat the previous step. When the device is found, select it, and then click Next.
If you've tried this step repeatedly and your computer still cannot find the device, check to make sure the device has fresh batteries.
If the device is a keyboard, exchange passkeys with the keyboard. If the device is a mouse, click Don't use a passkey. Follow the rest of the instructions in the wizard.