PC reboots instead of shutting down

[andygibbs]

Recently, my pc has been acting strangely. When i shut down it down, everything appears to be normal and the machine powers off, but then a few seconds later, it just boots up again. Looked on microsofts site and they advised disabling "automatic restart on system failure" in the advanced system settings.

Please help, currently I can only shut my PC down by crawling under the desk to flick the switch on the back of the power supply - this then results in my machine attempting a scandisk everytime I boot-up again.