I have configured MCE to support a set-top box, but the MCE IR (infrared) blaster does not seem to control the set-top box. Is there anything I should try?
Remove or reinstall the Microsoft eHome Infrared Transceiver driver under the Device Manager in the Control Panel. Alternatively, you can update the eHome remote driver from the link below. Also, make sure the LED controller cable (IR blaster) is plugged into your remote receiver and positioned properly over the remote sensor on your set-top box.