Remote control with multiple computers in one room

I've seen this somewhere, but I can't for the life of me find it again. There is a way of setting only certain remotes to work with certain PCs so they don't interfere with others. I have my HTPC and laptop in the same room, both with IR receivers - whenever I use the remote for my PC, the laptop ends up with all the signals too, and I come back to find it's playing a video or something.

Does anyone here know where that tutorial/registry setting is to change remote control channels? Thanks.

Found it! I will post it here for anyone else who wants to know:

Pair one remote to one system

If you have more than one Media Center system in a room then you may find that one remote will control all the systems at the same time. If you don't want this then there's a way of pairing a remote to a specific system.
To enable your Media Center to respond to a specific remote control ID do the following: press and hold the DVD Menu button on the remote control, then press a number button (1-8) for five seconds. Remote controls with visible LED signal indicators will blink twice to confirm the change. Then start up your PC, open Regedit again and go to:

HKEY_LOCAL_ MACHINE\SYSTEM\CurrentControlSet\Services\HidIr\Remotes\745a17a0-74d3-11d0-b6fe-00a0c90f57da

and in the key, CodeSetNum0, enter the number you entered into the remote