I purchased GTA III - I installed it and had lots of fun playing it. So much so that I decided to purchase GTA Vice City. Now the trouble begins. On installation, the game plays fine but with no sound (I can hear the radio in the car but no car sounds, gunfire, sirens, etc.).

So I go to audio options. The default is "Auto detect" - I cycle through a few names that I've never heard off - all are rejected except "Rad game tools RSX 3d audio." I have no idea what this is! I'm using the basic onboard sound of my Gigabyte mobo. Anyway, setting this option gives sound, but now the video is terribly slow. The game does not crash, but the video is very slow. I try changing video resolution, but that doesn't help.

Since my GTA III works great right out of the box, I decided to check that audio setting. It listed "Miles 2d positional audio" or something like that (it was the default choice). Not only can I not find this setting in the Vice City audio setting, I can't even go back to "Auto Detect" any more - that is being rejected as well as every other choice except the Rad game tools...

I did some searching around - some suggested going to DirectX audio settings (Run -> dxdiag) and turning off audio hardware acceleration. No luck. I found a video patch for Vice City, but that didn't help either. I've tried uninstalling and reinstalling the game, but I get the same results.

My specs appear to be well beyond the minimum hardware and even beyond the recommended hardware for this game. Any suggestions I could try?