Usually the system hanging while trying to perform a restart stems from a program not shutting down properly. This can happen with open background programs such as Antivirus, a torrent program, DVD burning software, almost anything.
Can you tell us what programs you use that are on constantly?
Or you can even check the event viewer. - Check your aplication log as well as your system log.
Its one of the fastest standard SSDs on the market. Can u tell him not to select restart, but when he see the option, just restart from the Start button.
Problem occurred during W 7 setup and thereafter, not linked to any particular running software. Have just discovered he's installed 32 bit version of Win 7, so 8gig RAM not much use to him. Advised him to get 64bit version, hopefully his restart prob will disappear after the next install...