Is there any registry file to disable changing time by users in windows xp?
I don't know a registry setting for this, but in my mind the correct way to do this is to join the useraccount to Users group and remove it from Administrators or Power Users -groups.
For example at Command prompt (DOS-window) you can do this: Check useraccount's groups and check group's menbers:
Add useraccount to local group:
Remove useraccount from local group
When in Active Directory (=Domain) environment this is a bit more complicated, but the principle is the same.
You can do this using
This only works when your user is not a local admin. When the computer is part of a domain, it's easier to push a GPO.