Log-Off

I work currently on a company of telephony and wireless technology. Our MIS Team is apart our IS Team, recently they made some changes at the policies of the users and when a users hits the shutdown button in windows 2000, it only gives the option of log-off. This is strange because before this it gaves us all the options, like restart and hibernate, but all of a sudden this is happenning. Could you please help me find out what they did ?