i was sure it had been mentioned, maybe not.
having said that, its pretty standard with anything on a computer that doesnt work to turn it off and back on again. games aint an exception. any problem, with anything, the first thing to do is turn it off and back on. hardware or software.
i had assumed people would know this, if that was an incorrect assumption, i apologise.
but for future reference, that is the first troubleshooting action that should be taken for absolutely everything.