' my bios does not recognize my hard drive or cd drive ' how do you know if your screen stays black?
are you able to get into bios and actually get the information on the screen?

what do you mean when you say ' i can't get setup' what are you trying to do ?

and don't worry about dell helpdesk, they are known for letting people down easily. Post some more details here and someone here at EE will come up with good advice.

so post more details please.

...also when did this start happening..?  Did something happen to the PC, like being moved, or the electricity supply or anything..?

yes i can get into bios and get info..my drives are listed as unknown.....my pc crashed and tried reloading windows xp...thats when things got tough....could not get to my hard drive or cd drive.....i replaced the mobo and hard drive.....no change..

i did not have any electricity problems or any physical damage...

it almost seems to me that something is between my bios and drives not allowing them to talk...i can't put a finger on it...

Well as I bet you know, there literally is something between the bios(mboard) and drives... are the drives connected by the same cable, ie: they plug into the one channel on the mboard..? or do you have a cable, say, from the hdd to the mboard, and another separate one from the cdrom, etc..?  Any spare cables you can try, if you havent already replaced them when you swapped the motherboard..?

lou, how comfortable are you around your computer? Can you do a bios reset?
Did you check if your ide-cables are fitted well?
As I understand till now you're able to see the boot screen, get into bios but beyond that point your screen stays black?
Did you check boot options in bios?
I know a lot of questions but give us something to work with.

MrAruba

this pc is 3 years old.....running windows xp...i have one hard drive,,,which is a segate....a cd drive and a burner,,,also a diskette drive,,,which is recognized in bios...

i did not replace the cables from the drives to the mobo....i think it would be unlikely that both cables are shot...one cable to the hard drive and one cable to the cd rom....i tried bios reset many times and no dice

when i press escape key from bios,,,i get on the screen"strike fi to retry boot,,,f2 for setup utility"  if i press f1 it repeats the message...i press f2 i can go to bios.....

on boot,,,,it tells my bios version,,,which is phoenix rom bios plus version 1.10 A03..the message is "performing automatic ide configuration".....then it says to strike f 1 to retry boot,,,or f 2 for setup utility...i can go to setup...thats it...   on boot,,i see the dell logo,,,then it goes to performing auto config,,,at that time i can repeadedly tap f 12 and it says boot device menu....i can press normal or diskette drive....so i would be able to put in a diskette...

i no there is a intel 800 chipset that is suppose to be in my system....maybe something with that?  i don't no whats between the bios and drives...i no the mobo of course...perhaps trying something through the diskette drive,,,only what?

Well, the good news is you are able to boot from disk.  I am assuming this computer is out of warrenty.  So you try this at your own risk!  I would suggest flashing the bios to the lastest version.  
First, go here and download the FLOPPY FORMAT package (BD820009.exe)
http://support.dell.com/support/downloads/format.aspx?c=us&cs=19&l=en&s=dhs&SystemID=DIM_PNT_P4_8200&os=BIOSA&osl=en&deviceid=308&devlib=1&category=1&releaseid=R49451

Now find a blank ERROR FREE (needs to be error free or new) floppy disk.  Stick the floppy into your working computer then run BD820009.exe from your harddrive, and click setup.  When it is done writing to the floppy, boot from it on the non-working dell.  Then follow the setup promots.  MAKE SURE NOT TO TURN OFF/REBOOT THE COMPUTER UNTIL THE UPDATE IS DONE.  After the update is done, the computer will probley reboot itself, when it dose this and you see the dell logo, power off the system for 30 seconds then power it back on and see if it sees the drives

i must thank icemanwol very,,very much...for getting me started on the right track....i did what you said with the ao9 flash.i'll go step by step so other people might gain insight.....the diskette would not boot on restart....so i went to the menu line as posted above and selected diskette and enter,,,no dice......then i loaded windows 98 startup diskette from the menu line and enter,,,it loaded......then i get an A prompt after loading win 98 startup diskette.....i had to type at the a prompt D8200A09.EXE...it did flash and now at present i have the ide cd-rom device listed in my bios...i tried the windows xp cd and got a trap message,,,an exception with a lot of words on the screen..i pulled out the cd and reboot and now i might try loading windows 98 with 6 diskettes from microsoft...so at this point i don't no what will happen.i will keep this post going of course..anymore input would be really appreciated..

lou

It does seem like you have possible motherboard or IDE controller problems. Another possibility is memory. You could try reseating the memory carefully and firmly (with power off, of course).

Make sure you have set your drives to MASTER and SLAVE and not cable select, i have noticed certin dell systems do not like cable select on certin drives.  If worst comes to worst, you could always buy a PCI IDE controller and disable the on board ide controllers.
IDE controller: http://www.newegg.com/product/Product.asp?Item=N82E16816102008&CMP=OTC-Froogle&ATT=PROMISE+FastTrak+TX2000+PCI+IDE+Controller+Card

thanks again icemanwol,,,i tried what you suggested and no dice....i think i might have to order that promise card....that dell bios flash must be real weird......can't really understand it.original equipment and not a good flash.....i'm nearly certain it is the flash......i could revert back to my original flash A03 and then up the ladder to A09....of course this could be risky...i'm assuming dell's site for bios upgrades would be the same as the mobo makers site..i'll try a little more on research and  then the promise card

thank you so much icemanwol for your help without you i'd be frustrated for many more hours...the key as you stated was dell does'nt like cable select on the hard drive.....thats where i went haywire....like they said to use cable select,,,,wrong.....i tried cable select on my new western digital no dice.....finally set it to single and wala! i am now loading windows any very happy...cost a mobo i did'nt need but i can live with that....thats again icemanwol!