If you do video editing on Windows XP, don't install the DirectX 8 SDK. It appears to install a debug version of the libraries (I think, most importantly, quartz.dll) that screws up, at the very least, ULead MediaStudio Pro and Scenalyzer. Probably other video editing software, too, because I think they all rely on DX for rendering. Boy do I hope that DX 9 is coming soon.