AGP video card to PCI video card...?

I have a Dell Dimension 8200 that I am upgrading. It had an AGP Nvidia 64MB Geforce 4 MX 420 card and I am upgrading to a PCI ATI Radeon X1300 256MB. I guess I screwed up and installed the new ATI card and drivers while the AGP card was still enabled/installed. The computer then thought I wanted to use both cards (for multiple monitors)...I never was able to get any signal from the new ATI card. So then I uninstalled the drivers for the AGP Nvidia card and restarted. I pressed F2 during startup and changed the video choice from AGP to AUTO (that was the only other option shown). Now when I start up, I can't get either card to do anything.

Is there any way to take out both cards and somehow do a hard reset to get things back to normal?

Someone please help...

THANKS!!|||Yes. Turn off computer and unplug it. Look next to battery. You should see 3 or four small pins with a jumper attached to them . Remove jumper . Turn on computer. It may beep but most likely not. Monitor will stay off. Turn off computer. Replace jumper and your AGP card. You may need to go into your device manager prior to all this and remove display adapters as well as any driver packs you have installed. You may have to google your motherboard to find location of your CMOS bios jumper(same tiny jumper different names).|||First of all only one of those cards can run. If you want two to run together they have to be the same model and capable of it. Most cards have two outputs on a single card for two monitors. Second of all the new card is not PCI, it's PCI-express. Big difference. Uninstall all video drivers in safe mode and plug in only the new one. Then install the new card drivers.