UNABLE TO OPEN ALL SAVED DOCUMENTS: WORD, EXCEL. PP, ETC..

NONE OF THE DOCUMENTS PREVIOUSLY SAVED ON MY COMPUTER IS OPENING. WHAT HAPPENS IS THAT WHENEVER I TRY TO OPEN A DOCUMENT, THE FOLLOWING MESSAGE SHOWS: WINDOWS CANNOT FIND “NULL”. MAKE SURE YOU TYPED IN CORRECTLY AND TRY AGAIN…

COULD YOU PLEASE HELP ME NOW?