Since yesterday afternoon, I have not been able to turn my laptop off. Using the 'start' button, I get the menu for 'Shut down' with options. Clicking on 'shut down' has absolutely no effect, neither does pressing any of the options. I have also tried pressing and holding down the on/off button, but this has no effect either. The only way to switch off last night was to disconnect the mains and let the battery run down. Eventually the laptop stopped working. However, when I plugged in again this morning, and hit the on button, it was as if it came out of the sleep mode, there was no usual start-up, showing manufacturers name, 'windows is starting' etc. Any ideas please?