Yesterday, when I switched on my laptop it failed to get going, it seemed to be loking on one drive for the startup, possibly the D drive, and when it couldn't find it, it kept on switching itself off, and having another go, getting stuck every time. It did this for a while, I unplugges everything and it made no difference and then I turned it upside down to see if I needed to change the battery or something - its actually on the mains, but anything was worth trying, anyway I gave it a tap or two, turned it over, and it started up properly. It did this once before recently, but its OK at the moment. I've now backed up everything I think is worthwhile onto a DVD, but I don't want to reset it unless I have to. I used to know how to get it to the blue screen, but have forgotten, so couldn't check to see where it was looking. Any ideas?