Gateway too proprietary? PLEASE HELP!

I took out the 30 gig hd running win 98 after running fdisk and creating one partition. I then put it in an external hd reader connected to my hp running vista (that shouldn't matter right)? It told me I had to format the HD so I did.

When I reinstall the HD into my gateway 450 desktop and tell the bios to boot from cd rom, it says "please remove all discs and press any key to restart". It does this with and without any disc in the drive! Pressing any key results in nothing more than a repetition of the error.

The lights work on my cdrom so i'm assuming it works.
WHY ISN'T IT RECOGNIZING THE CDROM TO RELOAD THE OS? I'm trying to load windows xp home btw.

When I try installing my new sony cd-dvd rom drive (just in case the cd rom drive is bad) it does not recognize that either :-(

I am moving and need to either trash this computer or get it to work!!!!!

Thank you anyone who can assist me :-)

Michele
iLn4cit@msn.com