Okay, here goes... I have Windows XP Pro SP2 on disc, & Windows Vista Ultimate on Hard Drive. I have 2 HDD's, one for Windows, & one to store my films, music etc. Since Vista is on the HDD i dont think i can install it. I upgraded it, but would rather have both as Vista may look the part, but i miss the efficiency of XP. Is there a way i can install both OS's, & be able to select an OS at startup, whether it be dual booting or going into the BIOS & changing the boot device? I burned the files for Vista to disc but i ended up with a Calibration error. So burning it to disc is apparently out of the question. Does anyone know a way around this?? Thanks for any help/advice you guys give me.