I have a client's machine that got a blue screen c000021a when booting. I know I can repair this by performing an in-place upgrade although she does not have the WIndows XP disk since she never created the recovery disks. I believe I read somewhere that I can download the Windows disk from Microsoft's site and use the product key on the side of the machine but no sure exactly where I read that or how to download the software. Has anyone run into this issue before? Does anyone know how I can do an in-place upgrade on a PC that doesn't have the recovery disks? If I use my own disk then it will ask for my product key I believe.