My macbook pro is not booting, please help me :(

Question

hello,
my macbook pro is not booting in OS X, it displays the apple logo and the spinning wheel, but a circle with a cross appears and the spinning wheel continues, please guys, help me
P.S: my MBP is boot camped

Answer 1

Well, sometimes you can gain access to the drive from another Mac connected to your computer via Firewire cable. It's called Target Disk Mode - Transferring files between two computers using FireWire. Or you already have backups. If you don't then you should consider a backup strategy to avoid this the next time it happens.
There are too many reasons for a drive to become corrupted within the normal course of use. A most common cause is abnormal shutdowns from power outages or not using the normal shutdown procedure because of a system lockup. Software glitches happen or you may be using software that is poorly written, and on and on.
If don't have backups:
Basic Backup
Get an external drive at least equal in size to the internal hard drive and make (and maintain) a bootable clone/backup. You can make a bootable clone using the Restore option of Disk Utility. You can also make and maintain clones with good backup software. My personal recommendations are (order is not significant):
Carbon Copy Cloner
Data Backup
Deja Vu
SuperDuper!
Synk Pro
Tri-Backup
Visit The XLab FAQs and read the FAQ on backup and restore.  Also read How to Back Up and Restore Your Files.
Although you can buy a complete external drive system, you can also put one together if you are so inclined.  It's relatively easy and only requires a Phillips head screwdriver (typically.)  You can purchase hard drives separately.  This gives you an opportunity to shop for the best prices on a hard drive of your choice.  Reliable brands include Seagate, Hitachi, Western Digital, Toshiba, and Fujitsu.  You can find reviews and benchmarks on many drives at Storage Review.
Enclosures for FireWire and USB are readily available.  You can find only FireWire enclosures, only USB enclosures, and enclosures that feature multiple ports.  I would stress getting enclosures that use the Oxford chipsets especially for Firewire drives (911, 921, 922, for example.)  You can find enclosures at places such as;
Cool Drives
OWC
WiebeTech
Firewire Direct
California Drives
NewEgg
All you need do is remove a case cover, mount the hard drive in the enclosure and connect the cables, then re-attach the case cover.  Usually the only tool required is a small or medium Phillips screwdriver.