How to Deprogram Mode on a Comcast Remote
The remote that comes with your Comcast cable box doubles as a universal remote. It can be programmed to control your television and DVD player as well (or any desired auxiliary equipment). If you've purchased a new television and wish to reprogram the remote to interface with the new TV, you can reset the original device's program. Deprogramming, or resetting, the Comcast remote is simple.
Press the mode you wish to deprogram (AUX, TV, Cable).
Hold down the "Setup" key until the previous mode key blinks twice. Roughly three seconds.
Press "9," "9," "4" on the number pad.
Press "Setup" again.
Press the mode button (from Step 1) twice. Now the remote is reset and can be reprogrammed for your new device.