I just built a PC, and all metal parts (excluding the case (My case is a NZXT H440, in case that matters)) give me a constant electrical shock, a bit pulsey.
It hurts a lot, so taking out and putting my GPU back in without touching any metal was a pain in the ass.
So PC power supplies only supply up to 24V, which you would notice, but probably not describe as a painful electrical shock. It's much more likely that this is an AC wiring problem, imo. I'd suspect your PC power supply first, then the power cable, then the wall outlet.
I have tried with and without a power brick. In fact, the issue remains even after disconnecting the PC from the wall power.
I'm not sure I understand you here. What is a power brick in this sense? This suggests that the voltage is not AC from the wall, but doesn't make sense based on what else you've said. AC at the wall turns into DC, which is stored temporarily in the power supply, but when you disconnect the power the AC leaves immediately. The DC voltages stored in the supply wouldn't cause as much pain as youre describing unless you were extremely sweaty or something. Or unless you're a wimp :-)
I do have a carpet, so that might be a problem, but notably I'm in the Netherlands - and in my room, there's only outlets with 2 holes - no ground, like this.
Carpet isn't the problem.
My power supply's plug however, seems to have a hole and side things, both showing the cable requires a ground. http://www.qiaopufactory.com/pic/big/16_0.jpg
Is this the cause of my shock problem, and is it dangerous? My case doesn't shock me, so if I just slap on the side panels and not touch anything, will I and my PC be fine? (And if I do touch the metal, how dangerous can it be?)
The lack of a grounding prong isn't the cause of your problem, though having one would prevent you from getting shocked when something malfunctions like it has. Voltage is somewhere it shouldn't be, so either a part is malfunctioning or there is a wire dangling and touching something. 240V is likely what is present, which can be very dangerous.
I would resume working on it after getting rubber gloves, and leave it unplugged in the meantime. In addition to your own safety, there's a strong chance that you could kill another part of your system, though it's working now. Many parts in a PC, like hard drives, are connected to the metal in the case. I'm frankly surprised, but glad, it hasn't fried something already.
If this were me, I'd leave it unplugged overnight, then quickly check to see if it still shocked in the morning. In the meantime, I'd get hold of where you got the power supply from and describe your situation. If the case doesn't shock after some time, recheck your power supply wiring and make sure an unused wire isn't touching metal somewhere. Barring that, it's a faulty cord or a bad power supply.
