MBP looping and won't start up

[owent]

Hey Everyone!

My MBP is looping on start-up. It goes to the white screen with the apple logo and that little wheel made of grey lines.

It just keeps spinning then after 30-60 seconds, it shuts down and restarts only do do the same thing again.

Any idea how I can fix this? I think I may have accidently deleted some system files. The last thing I was doing was deleting things from my Hard Drive.

Any help would be great!

Thanks!

 

[mulo]

1) dont go about deleting crap you dont know what is....
2) reinstall.

 

[owent]

won't reinstalling the OS wipe everything out? That's not an option. I have client work on there that hasn't been back up to my external hard drive yet.