Depending on your OS- try one of these on for size....
Here is a program called registry cleaner- use it if you don't want to do it manually.
http://www.vtoy.fi/jv16/programs/RegCleaner.exe
Try this link 1st, and follow the directions there.
http://63.231.44.178/board/showthread.php?s=&threadid=33630746
If that doesn't work- try these instructions...
Win XP- getting rid of ATI drivers (Or any drivers- just make the search changes) (Win 9x will be at bottom of page- 1st list is WinXP and2000)
WIN XP/2000
1. Go into the Control Panel and under the ADD/REMOVE SOFTWARE icon uninstall the ATI MultiMedia software and/or the ATI DVD software.
2. Uninstall the ATI drivers also found in the Add/Remove section. Once removed, it will prompt you to reboot....do so.
3. When returning to windows, the NEW HARDWARE FOUND wizard will come up and will tell you that it has found a new VGA card and will prompt you for drivers. Hit CANCEL!
4. Now, go to START - SEARCH - FOR FILES OR FOLDERS and do a search for all files and folders using the filename ati*.*
This search will normally give you 3 to 4 files found in your c:/windows directory and subdirectories (including the Windows/System directory). Select these files and erase them. Now go to your Recycle Bin and Empty your bin.
5. Next...time to go to your Registry. Go to START -- RUN -- regedit
Here go to key HKEY_LOCAL_MACHINE -- SYSTEM -- ControlSet001 -- Control -- Video . Here there should be 4 entries. 3 of them are default Windows XP entries and the 4th one is put in by the ATI drivers. Expand each one by one until you see ATI entries. Once found, erase the entire key.
Now repeat the same step above for the ControlSet002 key and the CurrentControlSet Key. Normally, whenever you erase a key in the ControlSet001, XP automatically deletes it in the CurrentControlSet section too. So if the ATI key is not found in the CurrentControlSet section, don't worry about it.
Once all keys are deleted, proceed to the next step.
6. While still in the registry, go to the key HKEY_LOCAL_MACHINE -- SOFTWARE section. Here you should find an ATI Technologies key. Select it and delete it. In that same section, look for an Installed Options key. Expand it and there you should find another ATI Technologies key. Select it and erase it.
7. Still in the registry, go to HKEY_CURRENT_USER -- Software and there you should find another ATI technologies key. Select it and erase it. Once all this is done, close the registry. the registry is now clean.
8. Close all windows and reboot.
9. When in windows after the reboot the NEW HARDWARE FOUND WIZARD will pop up again. Cancel that. Now find the new ATI drivers that you have downloaded and extracted and run the SETUP file. Once complete, reboot and you are done. You may want to reinstall your ATI MMC software and DVD software if you use them. DONE!
For Win 9x
1). Uninstall your current ATI display driver. Do this by going into your control panel and running add/remove programs. ATI Display Driver should be one of the first few on your list. Choose yes when it asks if you would like to uninstall. Choose no when it asks to reboot.
2). Remove all leftover .inf files. Windows will use these to reinstall drivers (or at least try) without giving you an option for a clean install. To do this, you'll want to do a find all files/search, which can be accessed via the start menu. Windows ME has it labelled as search, and I believe Windows 9x has it labelled as find. In the search window, you'll want to enter ati*.inf as the target file. Don't bother making it search your whole hard disk, instead, under the look in field, type in C:\Windows\Inf, and make sure look in sub-folders is checked. Now your set, click find/search. Delete all files which it reports (make sure the location is c:\windows\inf or c:\windows\inf\other, do not delete ati*.inf files in other directories, just in case you chose to search your entire hard drive). Once you've completed the .inf flush, you're now ready to move on.
3). Reboot your computer. Windows will load with a default VGA adapter driver, which the ATI uninstall conveniently installs for you. Little do we know, ATI forgot to take out all the registry settings, ack! Here's what you need to do...
4). Run regedit. To do this, hit Start, click Run, and type regedit in the field and press Enter or hit OK. The windows registry entry will pop up. There are two sections you'll need to delete garbage from, the first one being the key HKEY_LOCAL_MACHINE\SOFTWARE. Click the plus next to software and in the directory tree below it you will see a key labelled ATI Technologies, simply highlight this key and hit the delete key on your keyboard. Click yes to confirm removal when Windows prompts you. That will fix all previous tweaks you may have done, so you can ensure a fresh driver install at default settings. Now, on to the next key(s) you'll want to delete. WARNING! The following keys which I recommend you delete automatically assume you are using only one display adapter(video card) in your system. If you are using more than one, I will assume you are literate enough to know which keys can safely be deleted without mucking up your secondary adapter. Go to the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\DISPLAY, click the plus next to DISPLAY and you will see at least one sub key, normally labelled 0000. If your registry is dirty, you will likely see multiple keys, such as 0001, 0002, 0003, and so on. If you have only one video card in your system, it is now safe to delete every sub key of DISPLAY, including 0000. To do this highlight each key respectively and hit the delete key on your keyboard, click yes when Windows asks if you wish to remove the entry. Once you have deleted all keys, it is now time to close the regedit program and move on to the next step.
5). You will now need to go into your system device manager, which can be accessed in two ways. One, by right clicking on My Computer, clicking Properties, and then Device Manager in the following window, or you can access the device manager in your system Control Panel and double clicking on the System icon, and clicking Device Manager in the following window. Under Device Manager click the plus symbol next to Display Adapters, you will now see the Standard PCI adapter listed below. Highlight it and hit the delete key on your keyboard and click yes to confirm when Windows prompts you. It will then ask you to reboot your computer to finish removing the device, click no. Next step.
6). Extract/Unzip/Decompress your Radeon drivers of choice to a location which you will remember (I use C:\Windows\Desktop\Radeon). Once you have extracted the drivers, you can now reboot your computer to manually install them. I do NOT recommend using the ATI setup program to install drivers. When you reboot your computer, Windows will detect new hardware and ask if you wish for it to search for drivers. I always tell Windows where to search, and do not recommend you let Windows search automatically. Since Windows 9x and Windows ME vary slightly in this driver install process, I will assume you are familiar with basic driver installation and can handle pointing Windows to the directory which you extracted the drivers (i.e. C:\Windows\Desktop\Radeon for 7041 whql or C:\Windows\Desktop\Radeon\ATIDrive for all other driver packages). From here you may proceed to let Windows search the specified directories for the .inf file containing the driver install information, and the rest should be fairly self explanatory.
Happy Gaming!!!
Good luck