Posted 20 November 2012 - 11:38 AM
From what you say, when this happens again, use the up / down arrow keys to 'Start normally'. If this works, super ! And when it has got itself up and running, go into 'Control Panel' and create a restore point.
If it doesn't start, re-boot the computer, if necessary hold down the power button until it shuts down, and re-boot it. this time choose the 'Repair' option. You will get a screen up with a bar running right to left, this is just to assure you that it is trying to do something. It may take a few minutes before anything else happens, but either it will be successful - and the computer will start - or you will get a screen saying 'Repair failed' and asking if you want to try using a restore point. Say 'Yes' and you should be presented with a list of restore points. Pick the latest one and click on the button, and with any luck at all, your computer should start. If it doesn't, try an earlier restore point if there are any.
If this doesn't work, then it's time for a repair install and you will need your install disc. You will need to switch on the computer to get the DVD drive to open. Put the disc in the drive, turn the computer off, and re-boot it. It should now boot from the disc. At the first screen that appears, choose your language, and at the next one choose 'Repair', NOT 'Install'. It should now repair your installation and your computer should start running again.
If it doesn't, you probably need hands-on help. Any repair shops in your area ?