I recently wanted to adjust Windows XP's Visual Effects setting, but I couldn't find a Group Policy setting or a registry subkey to do so. I searched the Internet with no success.
Finally, I found the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\VisualEffects\VisualFXSetting registry subkey. The default value of 0 is Let Windows choose what's best for my computer. Change the value to 1 for Adjust for best appearance or 2 for Adjust for best performance.