Just a quick question. So I bought an xfx pro 550w power supply, but unfortunately, the order came in a European 2 pin plug instead of the uk 3 pin to plug into the wall socket. So can I just use a normal plug converter. Someone told me the voltages or something are different so I can't just use a converter.
You should use a grounded cord with it. An electronics or appliance place should have replacement cords.
As to voltage, a PSU like that one with full range active PFC can adjust to any input voltage over its range, typically 100V-240V.
The PSU automatically deals with the incoming voltage so you don't need to worry about that, it can handle from 90-264V usually so that shouldn't be a problem. I wouldn't use a converter as they are less than ideal, but if you have another computer power cord lying around you can use that, the end that goes into the computer is standard so they are interchangable.