Hotfix Q811493, it does slow down your computer.
I just uninstalled it.
I'm running over 800 MHZ RAM, and my computer was very slow.
Start, settings, control panel, add Remove, Q811493 uninstall.
I am about to uninstall the hotfix. I just got off a chat with Microsoft and they said they are working on a fix (no estimate of a release date). They further said to either uninstall it or disable my virus software (Mcafee).
I am running XP Pro and am the only one who uses this computer so I think I am safe (but are we ever really safe with Microsoft).