I had some problems with a USB TV tuner I just bought yesterday, it said it was Vista certified but it would not install the drivers that came with it, so I went to device manager and let it do an online search for any updated drivers and it found and installed one no problems, the strange thing is that it isn't for my tuner.
It found the Cinergy T xxs capture driver and my tuner is a Kaiser Baas KB201-1, I had a look on their site but I didn't see any drivers there but the one I got works fine anyway so I wasn't to worried.
Anyway I went into Windows 7 and thought it would find and install the same driver but it was unable to find a driver and the install disc wouldn't work either, so I ended up searching for the driver that was found on Vista manually and located it and installed it on Windows 7 and it works fine on that too now.