For some reason, I assme the answer lies in the system's reg. But I have two DivX codecs in Virtual Dub. The true DivX codec has the FourCC Code 'divx'. The other one has a FourCC Code 'yv12'. I did a search (including hidden files) for DivX.dll, and only the real DivX codec came up. Ok, so the codec is a vidc.yv12, in my Drivers32 fold in the reg. Is this safe to delete? I don't know if it's being used right now. I'm thinking that the vidc.yv12:divx.dll came from gordon knot. Can anyone verify that?