I've recently upgraded to an HD3870. Install seemed to go fine (Catalyst 7.11). Card functions fine in games and benchmarks (17,365 3dmark05, 11,447 3dmark06). However, every time I restart, I get a new device prompt, Windows detects a new PCI device, and wants to install. I just cancel out of the New Device wizard and its fine, but it is annoying. I can't figure out what device Windows thinks it has found. Any help would be appreciated.
There is a 'sound' driver on the Install CD that came with your card. That is likely the cause of what you describe. When the wizard comes up just stick the install CD in, the CD that came with the 3870 and go through the wizard with it.
I think the wizard should say something like, install hi-fi sound driver? If the wizard picks something like that up, that's probally why it keeps popping up asking for a driver. I don't know if it will effect other hardware than your video card, doubt it though.