RAM u plugged into the computer is not matching with your computer's mother board.
REMEMBER ! when u extra installed RAM in computer the following :-
1) Bus Speed
2) RAM (DDR1 or DDR2, SDR) what is RAM categories
3) Mother Board does support the high speed RAM or NOT (which will
be confirmed through NET by inserting mother board number, tags)
4) Notice: any beep heard when u start the computer.
Hopefully it will solved your problems.
with best wishes
bashir ahmed - Pakistan