Hi lindseyjena,
You have a bit of work to do in order to get that aftermarket videocard to work. It can be done, but you have several steps to perform.
First, get the 5.9 Catalyst drivers from ATI at
www.ati.com. If you've been trying to load/install ATI drivers, you should also download Driver Cleaner Pro and run it's Live Update (but not the program itself.. yet). You can get Driver Cleaner Pro at
www.drivercleaner.net
Now, last but not least, you need to get CPU-Z at:
http://www.cpuid.com/download/cpu-z-131.zip
Unzip CPU-Z and run the executable inside (cpuz.exe) We need to verify what Mainboard your EMachines has. It will be the Mainboard tab at the top. In that section it should say you have an AM37 motherboard. If you listed the proper EMachines in your post, this indeed should be the motherboard.
If you do have the AM37 mainboard you need to hit this link:
http://www.fic.com.tw/support/motherboard/bios.aspx?model_id=107
Download the top, VLB44 BIOS, unzip. Insert a blank floppy and format it in XP as an MSDos Bootable disk (right click the A: drive in My Computer, Select Format, click the "Create an MS-DOS Startup disk" checkbox) then copy the unzipped contents from the above zip to the floppy.
Now, restart your computer but start smacking the DELETE key to interrupt the power-up sequence. This will put you in the BIOS. You'll need to hunt around in here to disable the BIOS Guardian. You will also need to change the Boot Order to A:/Floppy is at the top of the list. Once this is done, save settings and exit. You should now boot off the floppy you made previously.
Once booted on the floppy, run the bios flash utility:
A:> awdflash.exe VLB44.BIN /nbl
When the flash utility comes up, it will ask you if you wish to save the current BIOS. Say YES. Save it as VLB41. It will then flash and verify the new BIOS. When this is completed, hit F1, remove the floppy and it will reboot into Windows.
Windows MAY ask you for your Windows KEY upon first boot. Your case should have a sticker somewhere on the side or back with this KEY. If asked, type this key in from the sticker on the case to get into windows.
After this, perform a RESTART in Windows and once again, smack DELETE to interrupt the power-up tests and get in the BIOS. You will have new options to change. You should hit/change the following:
a- turn the BIOS Guardian back on.
b- Change your boot order once more so it will boot the HD first.
c- You can turn PnP OS to "Yes"
d- Enable On-Chip USB as this may be set to Disable and any USB devices you may have will not work until you do.
e- Go into Standard CMOS Setup page and you'll now have a place in there where you can disable the on-board video. If you still have your new ATI card in, you can flip this to Disable, and next boot will come-up on the new AGP card!
You should then run Driver Cleaner Pro in Safe Mode as Administrator and install the 5.9 (or later) Catalyst drivers from ATI.
Good luck! Hope this helps.