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How do you clean the traces in the registry from previous display drivers? (with windows xp) >>
Good question

:
Read this
thread to the end. You can see its not quite cut and dried.
Here's my, "hey it works for me" XP Radeon driver installation steps:
*expand the drivers I want to use to a folder. (in my case, \video\6018\ )
*uninstall card from device manager (don't reboot yet)
*open regedit and look for and delete the registry entries discussed in the thread (keywords to look for: "Ati Technologies" "ATI*" "Radeon" "Rage" "Rage Theater" ect. ect)"HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services" keys begining with ATI* is where most mine are located YMMV.
*Search for "ati*.inf" in the "C:\WINDOWS\inf" folder and delete them
*Search for "ati* in the "C:\WINDOWS\system32" folder and sub folders and delete them (be very careful deleting these files to make sure they are related to the card)
Reboot
*allow XP to install the default radeon drivers, this will install the rage theater drivers for VIVO features everytime. reboot if it asks you.
*manually install the driver set of your choice as follows:
*device manager>right click video adapter>update driver>check "install from a list or specific location">check "Don't search, I will choose the driver to install">press "have disk">Press "browse"> point it to your drivers directory (in my case, \video\6018\ )> double click the "AtiDrive" folder>click "atiixpag.inf">pick your radeon model and install.
Your not done! Update the Rage Theater drivers manually as follows:
*Device manager>sound video and game controllers> update all the entries that start with ATI*>right click>update driver>check "install from a list or specific location">check "Don't search, I will choose the driver to install">press "have disk">Press "browse"> point it to your drivers directory (in my case, \video\6018\ )> double click the "AtiDrive" folder>click "atintwdm.inf">your driver should be listed>install>repeat for all the entries.
Now go to add/remove programs click on ati multimedia center and do a repair install, make sure you check all the features.
I use beta drivers, so I disregard the warnings about unsigned drivers. You should now have a somewhat clean installation of whatever driver version you picked. Beware that some versions break the VIVO functions,<6014 WHQL for instance> the 6018's I'm using are great when pared with MMC 7.5.
Forgot to add that playing around in the registry could result in severe self-inflicted injury to your rig, simply double clicking on the setup.exe file is probably the smartest way to go.