my mac book pro was running perfect an hour ago and is not very slow. I cannot even log in because I get the spinning beach ball and it is stuck at that screen forever.

Then your hard drive isn't full! That's the good news. The bad news may be that your drive is failing.

Try booting into your Recovery partition by holding down the command and R keys whilst booting. When you get to the Recovery screen, use Disk Utility to verify and, if needed, repair your hard drive. Hopefully, you'll get a green text message saying that the drive appears to be OK. If not, call back.

Clinton

OK - a couple of things to try: no guarantee that they will fix your problem, but...

Try resetting PRAM/NVRAM -> http://support.apple.com/kb/ht1379 and the SMC -> http://support.apple.com/kb/HT3964.

If no joy, then boot into your Recovery partition again and try repairing permissions. If that doesn't work, then do a 'fresh' installation of OS X (this is non-destructive and will not delete any of your data, apps, etc. - it will only replace the system components).

If all of that fails, I would try running the Apple Diagnostics -> http://support.apple.com/kb/HT5781 (since you've a 2013 machine).

Call back,

Clinton

Your hard drive/flash storage has failed.

Your best bet, at this point and since your machine is still in warranty, is to take your machine to your local Apple Store or an AASP and have them run their little diagnostics test so that they can repair/replace the drive.

Sorry to be the bearer of bad news, but that's the problem.

Good luck...

Clinton

Hi The Cipriani,

if it's a non retina MBP, then it's most likely to be either the hard disk or the SATA cable.

In my case it was the hard disk cable (SATA) showing an almost unoticeable mark on the surface, exposing the metallic wire. Replacing the hard disk cable fixed the issue and my MBP started working as before.

I am attaching a picture.

Regards

Valpix

You will need an appointment at your Apple store, if available, or call your Apple-authorized Service Provider to arrange to visit them.

An Apple store will do the evaluation for free, in warranty or out. AASP sets their own policies.