After a shutdown, my (Samsung)Windows 7 Home Premium laptop would not reboot completely, only getting to the blue screen with Windows 7 Home Premium at the bottom. The login icons would not appear so I could not get into windows (ie no msconfig, control panel, nada, really nada!).
I have lots of cr@p on it (apache, mysql, php, drupal, git, bash, putty, blah blah), so much that I really really didn't want to rebuild it. Everything's backed up but it was the reinstalling everything I squirmed at.
I tried EVERYTHING 'normal' to recover: - boot in safe mode (it wouldn't, it hung before getting there) - go back to previous restore points (it wouldn't and eventually there weren't any - I probably deleted them in my various attempots) - use auto repair (didn't work, it didn't see anything wrong!) - tried to use a backup copy of the registry (no change) - Hiren, etc etc.
Googling told me this is quite common and I couldn't find a reliable solution, certainly nothing that worked for me. So I was left with a laptop that seemed to get almost to starting, but didn't quite make it. It was utterly useless.