In Control Panel > mouse, Windows XP seems can't remember my cursor speed settings. I need to set it every time after restart. What could be wrong?
If your machine is managed by group policy, you need to talk to the people responsible for setting the policy. It's also possible that there's special software for the mouse running and that's overriding the Control Panel setting. Look for a mouse-related icon in your system tray (aka notification area) at the bottom right of your screen. Open it up and look for the option you want there.