Hi, when i try to shut down my PC it basically goes through the windows your pc is shutting down and then stops with the screen saying Shutting down your workstation or something like that, and it basically wont shut down. Now heres the odd thing, when i for example try to shut it down by the power button on the pc case or then restart it and use the power button it still wont, and also when i unplug it from the mains and plug it back in, it starts up but the OS doesnt start up (that is it starts up automatically... without me pressing the on button

)... as in the PC makes all the noises etc but the monitor is still black, its only recently started happening and i have no idea what it is except that it may be the motherboard, it had nothing to do with the hardrive as even if you unplug the hardrive it still wont shut down, so either motherboard or
PSU?
Thanks