No boot unless powered down.

[cycad]

Hi everyone.

When I have finished with my computer I always power down completely(switch off at the socket).With this procedure I have no problem booting,but if I shut down the computer leaving the power still on,it will not reboot until I switch off at the socket.
All I get is a whirring sound from the hardrive.

 

[Carolyn]

I would try another socket, preferably one that is not on a switch

 

[DalekOverSeer]

try setting your bios back to default, then set it back up the way you need it.

 

[James Colbert]

Possible PSU issues?:

Newegg.com - power supply tester