well I am kicking myself as I said I wasn't going to bother with flashing the bios as the system was fine however I just discovered that magic bios utility and decided why not test it out....flashed the bios and restarted the system only to discover that I could no longer boot...reflashed back to the older bios and the problem persisted...tried booting in safe mode only to have it hand at MUP or something...oh well trying a repair now on windows.