Strike F1 to retry reboot, F2 for setup utility Error

I own a Dell Optiplex GX150.  It runs Windows XP.

Step by step of what occurs with my computer:

* I turn on my computer
* The Dell logo screen appears
* The computer makes two beeping sounds
* Black screen with error message "Strike F1 to retry reboot, F2 for setup utility" appears
* I hit F1 but the error message just repeats itself below the first one.
* I hit F2 and look in the setup utility
* Everything looks normal in the setup utility. It reads:
Time: Current
Date: Current
Diskette Drive A: 3.5 inch, 1.44MB
Diskette Drive B: Not Installed
Zip Floppy Support: Disabled
Primary Drive 0: Hard Drive (it's in Auto mode)
Primary Drive 1: Off
Secondary Drive 0: CD-ROM Reader
Secondary Drive 1: Off
Auto Power On: Disabled
Remote Wake Up: Off
AC Power Recovery: Off
Fast Boot: On
Suspend Mode: S3

The back panel LED lights read A=Green, B=Green, C=Green, D=Yellow

I ran the Dell Diagnostics CD. It found 9999 errors. All of the errors looked like this:
IDE DISK 0 - Confidence Test
Status: Fail Status Code: DOS DDG- D Disk
Device: IDE_DISK_0 Test: Confidence_Test_Read_Test
Release:1068 Module(s): Disk
Msg Block 10041: Adress Not Found