help!Can't start computer from CD to reload XP

Hi guys, i have done this several times before on diffrent computer, but this dell desktop is not doing what it suppose to do.
I put the Win xp pro in the cd rom and restarted the computer after I change the boot to boot from CD, and computer go to tart windows. i chnagedeverything and reset to defult and also diconnected the hard drive. nothing works. on F8 i also selected CD rom , and didn't work. this is a 3 years old computer that getting very slow and has too much junk on it from the kids and I want to format it. any ideas how i can go around this.
thanks
Dell - Pentium 4, 3.00 GHz, 512 MB RAM, Windows XP

 

r you sure the cd works?

 

yes it's original new Cd, I also tried other CD a XP home edition and Vista ultimate too. CD rom works too...

 

ok, did it orig come preinstalled w/ vista? If so it is most likely a sata hdd and XP doesn't have the drivers for it.

If that's not it, give us a little more information on the desktop....

 

No the omputer came pre installed with XP pro and never been formated.
What desktop information do you need?
thanks

 

Still can do anythingwith this computer. I think I will try a new HD, if it doesn't work. It's going to down, from the 15th story window by gravity.

 

Do you get the message asking you to press any key to boot from CD? Are you using a wireless keyboard? If so, plug in a USB keyboard.

If you dont see the prompt message, its skipping the CD for some reason - double check the install disc in another system and verify its being recognized. The XP disc may have a scratch that nerfing it up...

If it works in another machine, its the BIOS setting. Double check it. Be sure its set as the first boot device.

 

No it skip the "press any key to boot from CD" message.
The CD works fine on another machine, I also have tried VISTA CD, the biose seting set to start from CD as first boot. it didn't work, I disabled th HD completely and though the system will start from boot 1 which is CD , did not work either. So I changed the HD to be Slave, did not work. I went through the setting of the Boise and start changing things one by one even tha they are not related. nothing working. So frusterating.
do you think updating the biose may work?

 

yeah - something is amiss. you should always see that press any key to boot from cd message.

a bios update wouldnt hurt it, especially if its on an older version of the bios. check dell support for the current bios and patch it.

very odd indeed.