MCE unable to recognize tuner

I recently replaced my MB and CPU. This necessitated the re-installation of XP MCE. After getting everything back up and running, I am unable to get MCE to recognize my tuner in Media Center. I've read dozens of discussion threads, downloaded the decoder check utility, updated the drivers, purchased new decoders and I still can't get Media Center to recognize the tuner. I can play commercial dvd's and previously recorded TV in Media Center and I can listen to the FM Radio that is provided on the tuner card but when I try
to set up the TV signal it get 'No TV signal found' message. If I try to configure it manually, then I get the 'Decoder in use' error when I try to watch Live TV. I'm getting frustrated and could really use some help!

Do you also have the latest MCE drivers for the card from the Hauppauge card or do you just have the drivers for the WinTV application? Does the Hauppauge WinTV application work?

By the way, what is your system config?

Do you also have the latest MCE drivers for the card from the Hauppauge card or do you just have the drivers for the WinTV application? Does the Hauppauge WinTV application work?

If it's happening after Update Rollup 2 installation:-

You receive a "Component Registration Failure" error message, a "Critical Process Failure" error message, or a "Tuner Not Found" error message after you install Update Rollup 2 for Microsoft Windows XP Media Center Edition 2005.
http://support.microsoft.com/Default.aspx?id=910905