I have had Windows XP Media Center installed and working on my Dell PC for four years. Because of viruses and other things bogging down the computer, I had to reformat it. I reinstalled windows, but now I'm having problems with my media center. There is no audio and when I try to go to Settings -> TV, it says 'The tuner hardware is either malfunctioning or not installed.' It has been working for years so there is no problem with the hardware. Any suggestions on how to get it working?