Bios screen (Setup) comes up when you select F2. You should start solving this by selecting Hard Drive Diagnostics from the Boot Menu F12. Run the extended test to see if your hard drive has failed. This can take a while. If the drive has failed, replace it. If it passes, boot to your operating system disk and try a repair. If you need to post again, mention your operating system.

Try Mary G's good suggestions first. But it appears BIOS isn't recognizing any SATA drives, so you may not actually be able to run the hard drive diagnostics.

In that case, you may need to reset BIOS to factory settings. Power off and disconnect the PC from the wall. Press/hold the power button on the tower for ~15 sec. Open the case and remove the battery from the motherboard. <ADMIN NOTE: Broken link has been removed from this post by Dell> It's a silver, coin-shaped about the size of a US quarter. Now press/hold the power button again for ~30 sec.

Reinstall the battery (right-side-up!) and close the case. See if it boots now. And if the battery is more than ~2-3 years old, it may have died and that's why the BIOS settings got scrambled. The 8400 uses a 3-volt  CR2032 lithium coin cell which you can purchase for ~$2-$3 at places like Walmart, Target, drug stores, etc.

Note: If you don't have an internal floppy drive in this system, you'll get a floppy drive error message when you reboot after removing/reinstalling the battery. In that case, run BIOS setup (F2) and set the floppy driver controller to DISABLED. Save the change and exit BIOS setup.

Ron

:emotion-5:

I also have an issue, I believe involves my BIOS settings.  This past Fri, after receiving a warning message that my system battery was low, replaced the system battery.  No problem; printed out all the instructions I would need; popped it in, closed the case and presto, all came back just fine.  HOWEVER, when I went to use the CD or DVD drive Sat night, nothing...........  I checked the BIOS and that section says unavailable, but I don't know how to make the CD available.  I would welcome any suggestions anyone can come up with.  Thanks in advance.

nhnonna in lakeport nh:emotion-2:

I also have an issue with the Dell Dimension 8400.  I hope this is in the right area to post; if not, accept my apologies.  I received an error message upon start up that the system battery had to be replaced.  Went to Home Depot, paid $4 for it, and put it in Friday morning.  I have the latest A09 bios update also.  Switch out went very well.  All my data was back where it was supposed to be and I was pretty proud.  I had printed out all the instructions from the 8400 manual on how to change the battery and followed all instructions; even printed out the setup screens in the bios, by taking digital pictures of each section.  When I went to use the CD on Sat night, however, nothing………  I tried to download new drivers from Dell but didn’t now what make or model the CD or              DVD were.  I tried a system restore….no luck there either.  The drives do not appear in my windows explorer, nor do they appear in the hardware device section of control panel.  I opened the machine up again, checked to be sure the drives were tight and they were fine. Still nothing……When I checked the Boot Sequence page, I found that the ‘onboard or USB CD-ROM Drive (not present) came up AFTER the battery install.  When I printed out that page, it WAS present.  Don’t know how to change this.  If anyone has any suggestions, PLEASE……I’d be very grateful.  Thanks in advance.

nhnonna in Lakeport nh:emotion-4:

You need to follow the instructions in this thread. It's about removing and replacing the CMOS battery in your computer,

thanks Skarpo - I'll give that a whirl tomorrow morning.  I believe I went into each drive and made sure it was 'on' but I'll doublecheck.  When you say 'reset your bios' what does that mean exactly?  I downloaded and installed it from the Dell site; is that what you mean?  I know the CD drive was Drive D and the DVD-R drive was Drive E.  Thanks again.

Are all your drives ENABLED? When you start the PC, press F2 to go into the BIOS, then go to Drives, press ENTER and go to each drive in the list looking whether it's ON or OFF. You should find SATA-0 ON, all other SATA OFF (except if you have more than one hard drive OR if you have a SATA optical drive), and PATA should list your optical drive(s). I have an 8400 with 2 optical drives, so both (Drive 4 and Drive 5) are ON. If they are ON and not showing any Drive ID description, try following the istructions to reset your BIOS and check again.

If you are not sure what is connected where, turn everything on and look if the system finds something connected (in the BIOS screen). Once you have identified all connected drives, switch off the drived that are unconnected.

STILL no luck.  I followed the instructions to reset the BIOS and I got again the message that SATA drives 1,2,3 were not found.  I'm so discouraged; I had hoped that would do the trick.  Any other ideas?  Thanks for your time; I appreciate it.  I have just run out of ideas myself.  :emotion-7:

nhnonna,

It isn't polite to jump into the middle of someone else's thread with your own problems. Next time start your own thread. :emotion-5:

SATA 1,2,3 should be turned off in BIOS, assuming you only have 1 hard drive. So run BIOS setup and disable them again. Also try setting the Drive Controller setting to RAID Autodetect/ATA. Be sure to save the changes before exiting setup.

There are no downloadable drivers for optical drives. They're all built into Windows. So until you get BIOS to recognize the optical drives, there's no chance they'll work in Windows.

Dumb question...You did install the new battery right-side-up, didn't you..?

Ron

I apologize again, as i did in my first thread; as I was not sure of protocol.

Thank you Ron - and yes, I put the battery in with the + side up as instructed.  I'll work on the bios again.  Thanks.  I won't respond to this one again.  I will find instructions on how to start my own thread too.

Sorry.:emotion-10: 

nhnonna