Installing your power supply is pretty straightforward, if it came with your case
it was preinstalled and if you took it out earlier to get the motherboard in, now
is the time to put it back. Otherwise a few moments of screwdriver work will
get the job done. Generally there will be a bracket on the top of the case where
the power supply is mounted and a few screws used to fix it in place. Some
cases place the PS differently, see the documentation that came with yours.
Some power supplies come with modular cables, so you can plug in only
those youll be using, now is a good time to figure out what youll need and plug
them in. Other power supplies have all the cables hardwired in, youll want to
separate out the ones youll need and neatly coil the remainder somewhere out
of the way.
If your power supply has a switch to select 115v or 220v make sure it is
set properly, this is important. Many newer power supplies can automatically
select and dont have such a switch.
Once you get the power supply installed you should plug the main power, a
20 or 24 pin plug, into the motherboard. There may also be an additional four
or eight pin power lead on the motherboard that needs to be plugged in, this is
usually located near the processor socket. Make sure you check the motherboard
documentation carefully for the location of the power sockets.