My girlfriend's MacBook Pro won't boot up?

My girlfriend has a MacBook Pro that won't boot up. She brought it over last week and I was helping her do some homework on it. We tried to restart it and it wouldn't do it on its own. I held down the power button to turn it off and then tried to turn it back on. It shows the Apple logo and the little spinning wheel, but it won't go past that point. I've left it up for hours and it never does anything else. What can I do to fix this? I only use PC so I know NOTHING about Apple. Is there anything I can try? She thinks her laptop is about 3 years old.

2014-10-12T16:10:52Z

There's no apple store here in town. I probably should have mentioned that.

d00ney2014-10-12T16:06:27Z

Macs are pretty reliable as a general rule, Take it into your local apple store. They are pretty keen on having trouble free machines.
That should also help her ascertain whether it was in good order at the time or purchase.
Even second hand they are not the cheapest computers.

Admittedly there may be a penny or two to pay (and bit more) especially if there is no warranty on her machine, or it is limited; but it taking it to an Apple Store will probably be the best course of action

Rich2014-10-12T16:05:27Z

yep... here is a few things to try..

http://support.apple.com/kb/ts1417
do a safe boot http://support.apple.com/kb/HT1564?viewlocale=en_US
open utilities and open disk utility and run the hard drive repair checks and permissions
http://support.apple.com/kb/ht1782

if she ever has browser adware/malware have her look here
http://www.thesafemac.com/arg/