Yes, you can run a 20 ga (my recommendation) wire to a metal rod drivien in to the ground. Or Run the wire to metal water pipe that goes in to the ground. Yes I would recommend doing this and no it should not damage your computer. Your neutral wire also runs to your chassie ground and should NOT have a signifiant voltage (Should not feel) on it.
Not sure about Indonesia, but in US nuetral and earth ground are sometimes/often tied at the main Fuse box.