In reply to Rampikino:
Which OSX version are you on, and which model of MBP is it? Some of the middle aged ones are very easy to open and get the HDD out. Can then put a new drive in and start agin, retrieving data from the (now external) old HDD afterwards using target disk mode as above.
Erm, you have backed it up in the past, haven't you? Time machine works pretty well and if you use it you will have a backup from about an hour before it went wrong.
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