given that this is most likely proprietary software, or at least a very specific software package written specifically for doing functions of your job (video store rental and such) you should probably call the program vendor for support. no one knows every program, but most programs do have some sort of fail safe to prevent catastrophic loss of data at the hands of unskilled users whose first recourse is always a hard reset (big NO NO!)
in short, call your district office, call your program vendor (look them up on google if need be) or talk to your boss. yes, you may be fired. or you may not. cross that bridge when it comes.