[zayde199]

heres my issue, i used to have windows XP and then downloaded the Windows 8 trial version. Then i decided that I didn't want it anymore and that I wanted to go back to XP. So I cleaned the hard drive and turned off the computer half-way and inserted the windows XP disc into the disc drive and in the command prompt changed the settings so that the computer would boot off of the CD drive...

...the problem is that after all of that whenever I start the computer I get a message that says "no operating system detected"

Can anyone help me ???

[Crazy10]

You need to reinstall Windows XP. There is no way to go back to Windows XP after installing 8.

[DoubleHelix]

You can't change boot order at a command prompt. You need to either change the boot order in the BIOS or press a key during boot to select the optical drive.

The error message you're seeing indicates the computer is not booting from the Windows XP disk.