okay here's a new one I certainly havent encountered. I shut down a laptop to replace a mouse button on the motherboard, switched back on and the win7 login screen has disappeared. all you get is wallpaper, ease of actions and the restart button, nowhere to sign in. safe mode all options the same and using a repair disc doesnt help as it tells me windows booted fine, tried to run sfc from a prompt. web search has similar complaints following windows updates over a year ago but all solutions involved factory restore or fresh install which would be a pain so before I go through the motions I thought I'd see if anyone has any ideas or has come across it before.