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I'm afraid I've corrupted my OS X install. When choosing to boot up with the system I get a grey screen (there's a short load sequence before this, after klicking the system icon in the bootup menu). I can hover my mouse around but there is no content. Earlier today I tried installing Windows 8 as a second system using Mountain Lion and Boot Camp 5.

I did the following:

  • Created a volume for Windows and installed Win7 + windows drivers
  • Began installing Win8, only to realize that I needed more disk space (apparently using the online upgrade requires a LOT of disk in between the switch). Chose to quit the installer.
  • Tried returning to OS X to delete the Windows volume but ended up with a grey screen.

Worth noting is that I see my OS X Recovery volume presented along OS X and Windows. My guess is it should be there but it could also be an indication that there is something wrong.

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Problem solved (for now). Started up OS X successfully in Safe Mode and was able to remove the Windows partition via Boot Camp Assistant. Restarted and everything seems to be back to normal.

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Upgrading to windows 8 creates a windows.old folder with the previous windows there (aprox 12~15 GB in size)

Its ok to delete it if everythinug works ok as you'll not be able to undo the upgrade after it. Truth be told, I dont think the upgrade is undoable anyway.

To delete the windows.old folder you'll need to take ownership of it first (Properties -> security tab -> advanced) and make sure that replace child permissions is checked

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