I have a Toshiba Satillite piece of **** from about 5 years ago, with Windows XP Pro SP1 installed on it. I was installing Microsoft Office Small Business Edition, and when it prompted me to restart my machine, I clicked "Restart Now." When it restarted, it said:

Operating System not found.

I tried booting into the Windows XP Pro CD, no luck, just skipped the CD and MSDOS boot floppy I tried using and went to the error message. I also tried booting into my LNX-BCC, SLAX, and KNOPPIX live cds, also without luck. My BIOS is set to boot "Floppy, CD, HD"

Two questions:

Why is the message there? Can I fix it (HOW!!!)?

Boot into the BIOS setup again and make sure that both the hard drive and CD-ROM drive are being correctly identified by the BIOS. The fact that it's bypassing CD-ROM boot, combined with the "OS not found" error, might indicate a lower-level (BIOS) problem with your IDE devices.