The E520 uses SATA hard drives.  You need to do one of three things: 1.  Go to System Setup (F2 on startup) and set the SATA controller to RAID Autodetect/ATA to put the controller into IDE compatible mode. 2.  Locate a standard internal 3.5" diskette drive and temporarily install it so that you can use a SATA drivers diskette to load the drivers at the F6 prompt in Windows setup. 3.  Go to the nLite site and follow the instructions to slipstream the drivers into a Windows installation CD that you make from your present CD and the SATA drivers file from the Dell support site. Dell used to ship Windows XP installation CDs that already had these drivers slipstreamed into them along with the computers that required them, but some shipments omitted these.  If you aren't using the installation CD that came with the machine, bear in mind that it must have at least Service Pack 2 integrated into it.  Anything older won't have drivers for your PCI-e video bus.
I'm w orking on a Dimension E520, trying to get into the repair console or reinstall the OS, When I boot from the CD it gets as far as the Windows Setup "SETUP IS STARTING WINDOWS", then I get the blue screen with the following information: A problem has been detected and windows has been shut down to prevent damage to your computer. If this is the first time you've seen this stop error screen restart your computer. If this screen appears again, follow these steps: Check for viruses on your computer. Remove and newly installed hard drives or hard drive controllers. Check your hard drive to make sure it is properly configured and terminated. Run CHKDSK /F to check for hard drive corruption, and then restart your computer. Technical Information: Stop: 0x0000007B (0xF78DA63C, 0xC0000034, 0x00000000, 0x00000000). Now I've scanned the hard drive and ran chkdsk using hiren's and it shows no problems. Also I used the CD on another computer and it worked fine. Can you tell me what the problem is? Thx
Blue screen when trying to troubleshoot or re-install XP using the 
installatioin CD