Last night I got Tuner Not Found error messages when trying to view and TV in Media Center 2005. This was after installing and windows express update. I looked at the update and it had installed .Net 2.0 for some reason it had turned off some services and now wouldn't restart them without an error message I used the following steps to fix these services, and once I did this, live TV started working again in Media Center 2005 with Update Rollup 2.  

1. Click on the Start menu, choose Run and type cmd, cut and paste each line and hit return after each line.