how do you prevent users from changing their usernames?

[GTS Jeff]

my roommate has this habit of changing his user accounts name on my computer to stuff like "1 am t3h 0wnaR11!!!!" so i want to restrict that from him without putting him on the limited account type. i looked thru the computer management options and couldnt find anything.

ideas? this is win xp btw, thanks.

[sin]

step 1. get over it and grow up

step 2. get banned for lipping off moderator

[Hash_man]

huh, did i miss something? who is lipping off a mod?