Starting, it remains in progress bar

restrepoja wrote:

When I try to boot My MacBook Pro 2011, it starts with progress bar until it reachs it full. Nothing else happens.

I tried many times and the answer is the same.

If a Safeboot does not sort it, run the FirstAid

Boot into Recovery (Command R) and from the dropdown menu: Utilities> Disk Utility>First Aid>Macintosh HD


Recovery http://support.apple.com/kb/HT4718

This sometimes happens when the Rotating magnetic drive is failing.

On the 2010 or 2011 MacBook Pro 15-in with dual graphics, it can be an indication that your Mac has failed to switch between the two graphics processors, leaving you looking at the previous screen, while the next screen (login screen or the DeskTop) failed to display.

When a drive has Bad Blocks, those blocks are re-read by the drive controller and fed through its error-corrector in hopes of obtaining good data. This can cause as many as 1000 re-reads before an error is generated. Needless to say, this slows your Mac incredibly, and may make it seem like it has halted.

A re-Install, even without erasing the drive, will provide NEW data for some Blocks the controller knows are Bad. In this case, it will substitute a "spare" block, from its private collection, as a permanent replacement for the Bad Block.

This will make the drive perk up and appear to be perfectly fine, for a while.

Very large scale studies on Google's server farms indicate that, over a very large sample, drives that accumulate more than a handful of errors will accumulate more errors over time, and will need to be replaced within a typical six months time.

Your actual mileage WILL vary, but you should now be keeping to an aggressive backup schedule, and thinking about what drive you would like for a replacement drive WHEN your drive dies.

Try starting up in Safe Mode:

Use safe mode to isolate issues with your Mac - Apple Support

OK, glad you got it sorted. Keep an eye on that drive and keep frequent backups.