You must not be booting from the cd drive if it says no hard disk. At the very beginning of boot, you'll see 2 function key instructions. Press the one--F12(I think?)- for Boot Menu. Then you can choose to boot from the cd drive. Here's the article to help correct her problem:

http://www.kellys-korner-xp.com/xp_sys32.htm

The reason you are getting this message is because the 8400's have a Serial ATA hard drive and this is the default message.

YOu need to go into the bios and change a setting to boot from the cd

what you need to do is

get into the bios f2 at startup

"Change the SATA Operation setting in the BIOS from RAID Autodetect / AHCI, the factory default setting, to RAID Autodetect / ATA."

im quoting a dell article that im having trouble linking right now but it is on support.dell.com


now you will be able to boot from the cd



your options at this point depend if you have data that you would like to back up on the system.


IF you do follow this
http://support.microsoft.com/default.aspx?scid=kb;en-us;307545

this will explain how you can "fix" the regisrty to get back into the machine


IF no data format reinstall now that you can boot from the cd


hope this helps




p.s. 8400's are pretty new so if your bought yours after 7-15-2004 you should have a ghost image to restore it to factory settings losing all data instead of trying option 2 this is alot quicker