Your post is a little vague. Are you talking about the boot order of your devices? If so, the exact procedure for changing the order depends on your setup, but generally there is a key you need to press during the BIOS POST that will get you into the BIOS setup. This key could be F2, F12, DEL, ESC, etc. It should tell you somewhere on the screen what key to press. Once inside the BIOS setup, look for something about boot order or boot device order and change it accordingly. It sounds like you want to boot from a Win XP cdrom on drive d: ?? If so, make sure that the CDROM device appears somewhere in the list before hard drive. (After the install, you should change the boot order back to something like FLOPPY, HARD DRIVE, CDROM)