Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I installed Windows 7 on my MacBook Pro without using Boot Camp. Now only Windows 7 boots; the Mac partition is fine but does not boot.

How can I restore Mac OS X?

share|improve this question

The function key is the key which gives you the boot options, i.e., OS X/Windows 7/HD recovery.

Remember to boot to OS X first to eject the Windows 7 disk. I used a boot disk which worked great. If like for me the CD option to write Windows data to did not work, try using a flash card but remember to unmount the flash card whilst in OS X mode.

share|improve this answer

When the Mac starts and you hear the chime, hold and keep the Alt key pressed. This should give you a selection of bootable partitions. Select the MacOS partition with the arrow keys and press enter.

Once you are running OS X, go to System Configuration -> Startup-Disk and select it as the startup drive.

share|improve this answer

Try starting up with the X key held down - this should cause your Mac to start up from the first Mac OS X partition it finds. Alternatively, hold down Option while starting up, and you should be presented with a list of startup disks to choose from - select the Mac OS X partition with the arrow keys.

If neither of these work, insert the Mac OS X restore DVD that came with your Mac, and start up from it by holding down the C key on startup. Then, use Disk Utility from the Utilities menu to verify and/or repair your hard disk, and use Startup Disk, also from the Utilities menu, to select your Mac partition as your startup disk.

A caveat, though: without Boot Camp, I'm not entirely sure how easily you will be able to boot back into Windows once you've got into Mac OS X (I presume you will know more about this than me since you did it at least once). Consider using Boot Camp or an alternative like rEFIt if you intend to switch between Mac OS X and Windows frequently.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .