Long story short, we've been given a Dell machine with Vista, as it was previously owned, I performed a fresh install using the provided "Operating System" disc, which gave a nice clean Vista Home Basic install. Lovely. Now yesterday, my girlfriend was using the machine, and was notified of updates needing to be installed, she allowed them to do so and then allowed the machine to reboot, unfortunately now after the initial Dell boot screen all that shows is a message stating "Missing Operating System". Putting in the install disc to attempt a repair also can not find the installed O/S. Having run the on-board HDD check, there seems to be no problems there either. Not having much experience with Vista, I'm a little stumped as to what to try next, so... any ideas?