XP resolution problem

Windows XP Pro
New 80 gig hard drive
Asus A7V Motherboard Slot A ??
AMD 1 Gig CPU
ATI Rage AGP

Problem: No display with more than 640x480

1) At first installation system did not want to display anything with ATI, so I used an old PCI video card to boot. Tried to install ATI drivers, but it wouldn't until I installed ATI card, so now had both video cards installed.

2) Got ATI driver for Windows XP off the 'net - ATI site.

3) Installed ATI driver, removed PCI video card.

4) For 4 days VIDEO DISPLAY WORKED FINE at 1024 res. Several boots, stable operating system, everything OK.

5) Today system would not come back from display off power saving mode.

6) I had to reboot, and no display at all.
a) At first there is a display while system boots
b) Windows XP logo screen visible
c) Display goes blank - orange light on monitor indicates no signal
d) No re-booting works.

7) To solve and get to 640x480 mode I went into Safe Mode and removed the ATI display adapter driver, which removed the adapter.

8) On reboot display is fine but is 640x480 with 8? colors. When I go to increase to 800x600 or 1024 resolution, soon as I hit "Apply" the screen goes blank with orange signal light indicating no signal

9) All works if I stay at 640x480

10) I have re-installed ATI drivers, have gone to ASUS site and downloaded and run AGP driver - still only works at 640x480. When I reboot after removing ATI driver Windows XP says it finds new hardware and loads the ATI driver, screen blinks, and comes back on, but at 640x480. Can't seem to get higher resolution.

Please help. I don't understand why it worked fine for days at 1024 resolution, then died.

 

Fixed

It's fixed.

I went to remove the ATI Rage and install the old PCI video card and noticed the ATI was loose in the AGP socket. I re-installed and booted and now can use higher resolutions. I don't understand how the loose connection would let it run in 640x480 and not higher, but whatever - it's fixed.