MacBook pro not loading

Hello,

I apologise if this question has been asked previously I have looked back but can't find a solution for my trouble.

I have a 15inch pro brought at Xmas just passed.

I have not used this computer for roughly 3-4 weeks as been using my iPad. Today I have gone to use the MacBook and I have a grey screen with the loading circle spinning not the rainbow coloured circle butone that looks like a flower.

I have left this screen for over 30 mins thinking it could be updating behind the scenes with not joy in loading.

I have gone to the utility disk and repaired no issues, still not loading. I have tried to reinstall but advises the disk is locked how do I unlock this?

Again I apologise if this has been questioned before

Thanks

If you purchased the machine Xmas 2011, it's still under warranty. Make an appointment with your local Apple store or dealer and have them trouble shoot it for you. The machine is loaded with Lion and does not come with a boot disk, instead it uses a Recovery partition.