The enter key of my laptop sudden stopping working?

I would try getting some compressed air. Sometimes called canned air.

Blow inside the keyboard, under and around the enter button and see if it helps. Do not hold the can upside down or sideways while spraying! It shoots out as ice and can hurt things further!

How about.. already replace the keyboard but still thesame enter key doesnt work. enter key only!!! even in bios enter doesnt work

To find out if it is a hardware or software issue, try going into the BIOS (Shutdown laptop>Powerup laptop>Immediately after pressing the power button tap the F2 or Del keys).

Once in the BIOS see if you can navigate to change settings with the enter key. If you can then there is a problem with your accessibility options in windows or keyboard driver. If not then you will need to take your laptop into a service centre for them to replace your keyboard.

Thanks
C