Saturday 1 December 2007 1.21pm
The 120/240 switch on the power supply must always
be at 240 when used in the UK.
Did the PC die before your friend moved the switch or after?
If it died after the switch was moved to 120, then you may have blown a fuse in the internal power supply. It is a simple and cheap matter to replace the fuse but, if you are not familiar with PC internals, leave well alone and unplug your PC from the mains right now!
This place does PC repairs
, but I have never used them and cannot vouch for how good they are - give them a call.