Mac won’t boot after installing updates on Windows partition

bootmacosx lion


I have an early 2008 MacBook with Mac OS X Lion installed. I made a partition with Windows 7 Ultimate which I can boot into by holding the Option key on the Mac keyboard.

Boot Issues

After installing updates on the Windows partition I can't boot the Mac anymore. It won't boot with the Option key held down, it only shows the mouse pointer and nothing else on the screen. Normal boot freezes on gray screen, safe boot doesn't work. I have tried all of those.

Additional Information

I don't have another Mac to do the FireWire boot. I also don't have an OS X installation disk, so I can't boot from disc. What causes these problems? I do have a Mac OS X Lion installation USB drive but I don't want to setup OS X again and/or loose my data.

This is the second time this has happened with this Mac. The first time I didn't even have a Windows partition on the machine, and I suspect that the first time these issues were caused by Firefox updates. Any advice?

Best Answer

There are two things that you can try:

  1. Power on the notebook holding Option+Command+P+R to reset the PRAM. This will force the EFI to search for a Mac OS X partition to boot.

  2. Power on holding Command+R to boot into the Lion Recovery system. From there you will be able to run the Disk Utility and hopefully repair the damage that Windows did. Worst case it will allow you to reinstall Lion.

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