Quicktime 7.7.3 update problem

Windows XP Media Centre Edition SP3

Just updated to Quicktime 7.7.3, but just as it finished, a message came up saying that files that could affect the stability of the system had been changed, and that I should insert Windows XP cd2 to reinstall original files! There was no option to stop it. I don't have this disc anyway as the operating system was preinstalled when computer purchased.

If I was informed before the update, I wouldn't have bothered.

What is going on?

Would uninstalling Quicktime solve this problem?