Administrator Cant Access Task Manager/run

I turned on my computer and found out that my regular user cant access task manager/run or turn off the computer. i am the only user on this computer and there is no network. the user is listed as administrator and i can change/create/delete other users which i tried. i created an admin user and that guy could do everything except access other user files. i looked into Administrators group and both were listed. when i do ctrl+alt+del it says Task manager has been disabled by computer administrator. but there's no administrator. there's a win98 computer that's connected to this one. but it's only used for internet by people who call a browser the internet every time my computer boots up it goes to a bios where date and time are change to weird numbers every time