Hey guess what, I lied when I said Doom 3 worked fine. Well, it used to, at any rate. Now no 3D games work at all. It's not just apps either, it's any 3D application at all. (I tried some Winamp visualizations that use 3D accleration.) They all seize up and stutter like mad. I guess my video card is dying. Excellent! Just what I need - another expense... Great timing! (On the other hand, my card is an aging Geforce 4, so maybe now's the time to upgrade to a DX9 capable card.) I did a completely clean install of Windows and added no drivers at all except for DirectX9 and the mobo, video & sound card drivers. Exact same results. Well anyway, apologies to Valve, I don't actually know if your program works or not since my computer is clearly messed up. (Although I have read that many people are having other sound stuttering problems with HL2.)