computer not restarting

[slyfox]

i hv gone thru a lot of posts regarding computer restarts instead of shutting down or rebooting unexpectedly when working.
i have a problem that my computer is not restarting. it is shutting down peacefully but when i restart from start>turn of computer>restart it hangs at the message "windows is shutting down"
this is the problem with linux too.

[shantanu]

there can be multiple reasons, for some i am not sure , but it might help. try checking your PSU( SMPS)(power supply unit) , then check your jumper for restart on motherboard (it might not help) . also check the BIOS settings for ACPI and power..

[ravi_9793]

try this:
This may help you:
http://www.techhunt.org/node/10