Windows: If you've been in the TV tuner game for awhile, you may have a decked out DIY DVR with more than a few tuners. Free app TunerSalad will let Media centre accept up to eight, raising the original limit of four.
TunerSalad is an extremely simple, one-click tool for raising Media Center's limit. Just open it up, select your region, and hit "Increase tuner limit". TunerSalad will double your tuner limit, so you can record all your shows at once. Hit the link to check it out.
TunerSalad is a free download for Windows only.