Windows laptop won't boot -

Try pressing the F8 key at start up. This should take you to safe mode, from here you will be able to shut Windows down properly and reboot without the loss on any data except for what you were working on at the time of the power loss. If it won't let you do this and stays in the same loop, it could be that the hard drive crashed and needs replacing. I don't do data recovery from a dead hard drives, so I can't give you an estimate on that, but a hard drive replacement, system reload with drivers and updates will run anywhere from $150 up to $600 depending on what you want.