When I first started the PC with a power supply board, I realized that its earthing is not working. I tested the CPU Cabinet with a tester and it glows red fully and the cabinet was giving mild shock. To eradicate this problem I took a thin copper wire and join one end to one of the screws of the cabinet and other end to the nearest earthing point. Since then the PC runs fines. but my question is whether it is unsafe for the Computer? If not, then should I keep it unscrew during storm and lightening?