You do not want to do that. What you need to do is find out what is making it reboot and fix the error.

Turn off the auto reboot and you will get an error code. copy exactly what the code is and post it back in this thread.

To turn off auto reboot:
start > r clk "my computer" > properties > advance tab > start up and recovery section settings button > uncheck the auto restart box and apply ok out.

The next time you reboot or start your computer it should show the error message.