AFTER UPDATING MY WINDOWS TO 8.1,I FACED A PROBLEM IN SHUTTING 

 DOWN MY COMPUTER.WHEN I SHUT DOWN MY COMPUTER MY DESKTOP 

APPEARS  BLACK,BUT STILL PROCESSOR GETS RUNNING AND  KEYBOARD

 LIGHTS  ARE ON.

THE SOLUTION IS:

STEP 1:PRESS THE WINDOWS KEY IN YOUR SYSTEM.

STEP 2:IF YOU ARE ON THE START SCREEN, TYPE AS "power", YOU CAN SEE 

SETTINGS OPTION,CLICK THE SETTINGS OPTION AND SELECT "choose what 

the power button do"

STEP 3:OR ELSE SIMPLY TYPE AS "powercfg.cpl" IN THE RUN DIALOG BOX.

STEP 4:  IT WILL OPEN POWER OPTIONS WINDOW ,SELECT "what the power 

button do".

STEP 5:YOU WILL FIND THE "TURN ON FAST START UP OPTION" IN THE 

BOTTOM  OF THE PAGE.DISABLE THE OPTION.AND CLICK SAVE CHANGES 

BUTTON.

STEP 6:IF THE OPTION IS GREYED OUT CLICK ON "change the settings that are

 currently  unavailable" AND PROCEED WITH THE SAME STEPS.

STEP 7:NOW YOUR PROBLEM WILL BE SOLVED.