Is your wall socket that you plug the PC into a 2 prong or 3 prong wall socket? You most likely have a grounding problem. You need to check if your wall sockets electrical sockets are properly grounded. You can get something like this, but for your country's electical system, to verify grounding. https://www.amazon.com/Sperry-Instruments-GFI6302-Receptacle-Professional/dp/B000RUL2UU/ref=sr_1_3?ie=UTF8&qid=1525410515&sr=8-3&keywords=wall+socket+tester&dpID=41lRWPMgkJL&preST=_SY300_QL70_&dpSrc=srch