Problem UNABLE TO CHANGE PRM :8000 (PWE)

DEAR GUYS,

PLS HELP ME ON EDITING PARAMETERS.

I HAVE A KINGSBURY VTC-3, GE FANUC SERIES 15-TT
I BOUGHT IT A MONTH BEFORE , I DONT HAVE ANY MANUALS FOR IT.
I WANT TO CHANGE SOME PARAMETERS OF STROKE LIMITS AND INPUT UNITS, ETC...
I HAVE GONE THROUGH NO.OF SITES WHERE I LEARNED TO CHANGE PWE FROM 0 TO 1
WHILE TRYING THAT IN SETTING PARAMETER 8000 , PWE TO 1. IT BLINKS FOR A FRACTION OF SECOND TO 1 AND THEN COMES BACK TO 0. ALSO IT GENERATES ALM , PARAMETER ENABLE SWITCH ON. EVEN IF PWE IS 0.
ALSO THE MEMORY PROTECT ON OPERATOR PANEL IS OFF.

KINDLY GET ME THROUGH THIS...
YOUR HELP WOULD BE APPRECIATED,

THANKS IN ADVANCE...