Are you sure that you really uninstalled your video card? coz uninstalling the driver is a bit complicated than you think. here's a nice guide got this from tweakrus.com. if you'd done that and still experiencing problem, check if you enable your AA and AF in video card settings. if its enable try and disable it or set it to application controlled. (although sorry im not familiar with ATI coz i only use NVIDIA)
Warning: If you are on a network and you are not the network administrator, please don't do any of this. Make the IT people earn their money. They'll thank you later.
General Video Driver Uninstall/Install
1. Unplug nic card or modem from net or disconnect. (Driver Cleaner ReadMe)
2. Disable any AntiVirus Software. If you don't disable, it could give you trouble. (Driver Cleaner ReadMe)
3. Uninstall current vid driver (If you have an nVidia mobo and a nVidia vidcard, make sure you only uninstall the video driver, not all nVidia drivers or your mobo will lose its drivers also.)
4. Reboot
5. As the reboot comes up, after the quick memory test and hard drives have been recognized, hit F8 and enter "SAFE MODE." On some boards if you hit F8 too early you will enter other utilities. OR you can run MSConfig.exe, hit the BOOT Ini tab, and check /SAFEBOOT.
6. On reboot into safe mode WinXP SP1/SP2 will auto detect and ask you to install drivers. You should be able to can cancel out of the auto install hardware wizard move to step #7. If you can NOT cancel out of auto detect wizard then, navigate to device manager->display adapters->highlight (nVidia, ATI, etc.) and click uninstall or remove but don't reboot. (From Driver Cleaner ReadMe, modified for clarity by Rike)
7. Run Driver Cleaner with the filter for the driver (nVidia, ATI, etc.) you just uninstalled . Quit and restart into the normal Windows mode.
8. Install new vid driver. Note for SLI users: sometimes the driver doesn't install for both cards. To ensure proper installation, you should check in Device Manager to be sure the driver is installed for both cards. If it isn't, you should right-click on the yellow-question-marked card and click on Update Driver.
9.. Empty the recycle bin and Reboot
10. Redo what was undone in #2 & #1, in that order. Reboot if needed to re-establish Internet connection.
11. Enjoy
Some people skip steps without problems. However, I should note that this is the safest, most stable method that we have at this point.
If you know any steps that should be added or removed, please post them on this thread. Also if you have another method you prefer, please add to the body of knowledge here. I will update the top post as new ideas are posted.
Thanks to all who have contributed to this thread so far. Originally compiled by Rike.
NOTE: This is from the Driver Cleaner readme;
nVidia:
1. Unplug nic card or modem from net or disconnect
2. Remove nvidia from add/remove programs
3. Reboot into safe mode (F8 during boot up)
4. On reboot into safe mode WinXP SP1/SP2 will auto detect and install drivers. Just let it do its thing. If you can cancel out of the auto install hardware wizard then skip the rest and run Driver Cleaner! If you can NOT cancel out of auto detect wizard then...
5. Navigate to device manager->display adapters->highlight nVidia and click uninstall or remove but don't reboot
6. Disable any AntiVirus Software (If you don't disable is than it could give trouble)
7. Run Cab Cleaner (not needed, but recommended)
8. Run Driver Cleaner
9. Empty recycle bin and reboot
10. Install the new drivers