cant boot from windows xp disk

[enz660]

in the bios, it set to boot from the cd first, yet it does not even ask me "press any key to boot from cd". I press f8 before the boot and select cd and it does nothing too. Any idea why it does not even see this disk? The back of the disk looks fine too... no scratches.

Mind you, i have windows 7 UPGRADE installed, but the cd key wont work cause its an upgrade so i shut off the computer. Upon trying to clear the hdd just to install xp (boot from xp disk) the screen comes up from windows 7 asking me which method I would like to boot (safe mode, normally, etc).

I read this may be because windows 7 installs the boot.ini on the hdd that has priority over the BIOS boot sector?

[Raddave]

Try this... Pull the Hdd, hook it to another machine as a slave or secondary hdd delete all the partitions on the disc, 0-write (zero-fill) the disc(including the MBR), then reformat. If you dont have any 0-write software you can get it at comodo...its freeware...the comodo system cleaner tool. Under the wiper section is the 0-write options.be careful that your wiping the disc you want to wipe. Then put it back in the machine and give it a go with the XP disc