Yep you read that right I have a Socket 775 cooler on my old 478 based system. Firstly a bit of shameless self promotion Here is the project log for my 'Retro Pentium 4': Here! My youtube channel also has some neat stuff and some rambling (so be warned): https://www.youtube.com/user/FrenzyUnit/ So what am I using? Well I'm using a Cooler Master Hyper TX3 EVO You can find the details here. So how did I do it? Well this is the tricky part but fear not for I am awesome and I shall tell you! Firstly I looked at the underside of the cooler and roughly attached the brackets, I then took the plastic retention bracket off the Pentium 4 motherboard and used it as a guide to locate the brackets. All that was really required was to use one included screw per-bracket and use the holes closest together, but here is the problem. The brackets will overlap. So how do we secure them without cutting half the brackets off? We overlap one of them but before installing the 2nd bracket to the cooler we use the screw hold furthest away to put a screw in but not fully tighten it. You want to get the screw to the same hight as the bracket already fixed down then install the 2nd bracket. The screw under it will act against the bracket and force it to stay in place. Really this whole thing is just a case of: 1) Overlap the brackets 2) use common sense That's all there is too it. If you want to try this out but get really stuck I'm happy to make a video showing the whole process so just comment on here or preferably on youtube (as it notifies me). Here is some pictures of the finished thing and thanks for reading!