Ok, here's my problem:

Running Vista Home Premium 32-bit. Have a Hauppauge WinTV-PVR 150 working with mediacenter. Everything's set up and working, apart from the poor onboard Intel GMA graphics. Recently installed a Gigabyte Radeon HD 3450 (this one) for the added features and hardware-assisted decoding (not to mention audio over HDMI is great. It's actually an HTPC setup for my dad; whos not too computer literate and the less cords the better )

Suddenly Vista MC complains that it cannot detect tuner hardware. A quick check of device manager shows that all the hardware is set up, drivers installed, and (according to windows, anyway) functioning correctly. Googling the problem results in a possible fix (setting "Media Center Reciever Service" as local system service or something - cant remember exactly, did it step by step from the guide on HP website) which did not help. All other information seems to end with people throwing up there hands and saying something like "sometimes it happens, can't fix it".

I know the tuner works, other apps can use it. The problem persists without the radeon present.

Ideas? Please?

Can't help, got exactly the same problem. Have just posted a request for help myself. My tuner is a Happaugge WINTV 4000 and worked well when I first installed it but now MC does ot see it even though DM shows the driver is working. dansyman

Same problem, Pinnacle PCTV-80e mini stick. Installed it using the "Windows Media Center" option on the CD, and MCE did not detect the tuner at all, then tried installing the full suite, and now MCE detects it but when I try to set it up using United States as the region, it says invalid region. Tuner works just fine with the software that came with it.

Yep happened to me too, hauppage wintv pvr 150 same as the 1st post.

My problem was me installing and not integrating the mce tv pack...once integrated with vLite and a fresh reformat all is working again