Macbook doesn´t start!!! Urgent

Disconnect any other drives.

Insert the Snow Leopard disk and reboot the computer holding c, you will boot off the disk.

The second screen in is a menu called Utilities, select Disk Utility.

On the left, select your boot drive and click Repair Disk

If Repair disk gives errors it can't fix, then please tell us.

When that's done, click Repair Permisisons, you can ignore what it says.

Try to reboot the computer and see if that works.

If that doesn't work, reboot the computer off the disk again and on the second screen simply install OS X.

What will happen is your messed up OS X will be overwitten with the new one, but your files and programs will remain on the comptuer.

If your concerned about taking this step, and/or don't have a backup of your data, then consider using computer services to recover your data before you acidentially delete it.

If you decide to do this, wait until you get updates for all your third party programs or verify with the vendor that there are no problems with OS X 10.6.8 before using Software update.

After the successful reinstallation, are you still getting the flashing question mark when you try to boot? If so, try this:

Resetting your Mac's PRAM and NVRAM

Some of your system preferences will be lost, as stated in the article. The data on the drive won't be lost, but you had better have backups, or you're in big trouble.

Is it possible for you to get a large external hard disk drive that you can a) create a bootable partition on and b) backup your internal drive to? Sounds like you may have bad blocks on your internal drive. If you are using less than half of your internal drive space, you could try partitioning the internal drive and installing a system on it but that is risky if you do not have a backup. If you get an external drive, make sure it is Mac bootable.

Jenson11 wrote:

After resetting are all data lost?

Going by what your saying, just OS X itself is hosed and not booting, your hard drive seems fine and your data should be intact.

However the first order of business is to get a copy of your files off the internal hard drive.

You didn't state what year or model is your MacBook Pro is, but you can get a powered external Firewire and/or USB drive connect it, hold c and boot off the installer disk again and use Disk Utility to format the (careful!!) external drive HFS+ Journaled. GUID partition.

Then quit and install OS X onto the external drive.

Once you do that, reboot and hold the option key down, you can then select the external drive to boot the computer and access your files on the internal hard drive and transfer them to the external boot drive.

Once you have done this, we will begin the next step. 🙂

Mac OS X 10.5, 10.6: Erstellen von Sicherungskopien und Wiederherstellen Ihrer Dateien