Does your computer have an equipotential terminal on the back? It's a metallic rod with an inverted Deathly-Hallows -ish kind of sign:
You can use that terminal and connect it directly to some sort of large metallic body (preferably unused and with low chances of coming in contact with) like a heater (one of the old one that come pre-installed in the room). Not exactly the safest option, but it can resolve this matter. Also the cheapest.