Still a lot of replies ITT with are either imprecise or flat-out wrong.
Once again, there are two types of computer power supply units available for desktop PCs in ATX (and mATX etc.) format.
1.) Lower-spec PSUs: These feature passive PFC. Those PSUs will have an input voltage selector switch. It is imperative to have the switch set appropriately. Connecting to the wrong voltage range will immediately and permanently destroy the PSU. (At the very least, you'll fry it for sure when the switch is set to 115 V and you hook it up to 230 V.)
2.) Higher-spec PSUs: These feature active PFC. No input voltage selector switch. Just hook 'em up. They'll work with all input voltages in the range of 80 V to 240 V or so.
Again, if you have type 1, it is of critical importance to use a screwdriver or your fingernail to put the selector switch in the correct position. The switch would be on the back of your desktop's case near the AC power plug. If no such switch exists, it is relatively safe to assume you got a type 2.) PSU.
Originally Posted by
WorldLux
And there are no indications on the back of the desktop?
Usually, there will be a fan which exhausts air out of the back of the PSU. (That's what's facing towards the back of the case.) So no space for a big label with specs. Instead, the label with the PSUs specs will typically face the inside of the case. Thus you'd have to open up the case to inspect the label.