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I tried to install Boot Camp to my iMac and I installed windows to the wrong drive. Instead of Boot Camp partition, I installed it to OS X :( So now I cannot repair the drive using disk utility because i grayed out. The drive is now called "disk0". I tried to reinstall OS X using the Mac OS X install disk but it cannot see the drive. the drive is not even on the list. How can I get it back, PLEASE HELP!!!

FWIW when I boot up my computer without the mac osx install DVD, it says "no bootable device -- insert boot disk and press any key". So it's obvious that the mac partition is overwritten by windows (read first post). Here is the description info of the main drive and the partition display from bottom of page when i select them from disk utility.

298.1 GB hitachi HDT725032vla360
Disk description: Hitachi HDT7250...
Connection bus: serial ATA 2
Connection type: internal
Total capacity: 298.1 GB
Write status: read only
S.M.A.R.T status: verified
Partition map scheme: unformatted

Disk0 (where it used to be Macintosh HD)
Mount point: /volumes/untitled
Format: windows NT file system (NTFS)
Owners enabled: No
Number of folders: 0
Capacity: 298.1 GB
Available: 127 GB
Used: 489.4 MB
Bumber of files: 3232
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As already stated by Mike, when you use Disk Utility from the install DVD, the "erase" and "delete" partition options should not going to be grayed out.

Look at the following image. Notice the important information, you have to select your DRIVE and not the partition. Then you have to select "Partition" in the tabs and finally click the little "minus" sign (which is Grayed out in the image).


Now when you boot with your Install DVD, you can open Disk Utility from the Menu during the initial stage of the install, when you're still being "welcomed" to OS X's install.

Try it from there and DiskUtility will launch (it will take a few seconds, since the DVD drive is not as fast as a Hard Drive) and try to remove the partition from there. Remember to "Apply" the changes.

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I know it's hard to believe but the drive does not allow me to click on the plus or minus buttons because all buttons on the page are grayed out and not active at all. Same goes to "first aid" and "erase" tabs. – Jon Jan 31 '11 at 20:07
Is it possible to post a screenshot or even a photo of your screen? – conorgriffin Jan 31 '11 at 22:30

Boot the install disk and run Disk Utility from that. You can then use it to repartition the drive, and reinstall OS X into a new partition.

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But it does mean you've lost your data and will need to restore from backup. – user479 Jan 31 '11 at 6:40
@ mike, I cannot re-partition the drive, the options are grayed out. Also the drive is there but it listed as "disk0" which is windows. @ Randolph, I have time machine and backed it up but when I try to restore, the HD is not listed as a destination – Jon Jan 31 '11 at 7:01
@Jon make sure you select the entire drive in disk utility, and not just the partition. It won't be able to change the partition independently, you'll have to do the entire drive. – xdumaine Jan 31 '11 at 13:05
yes i tried both main drive and the partition and that didn't work – Jon Jan 31 '11 at 20:14

If you have access to another computer, get an Ubuntu livecd and use gparted - I've found that gparted can be successful at formatting discs that other programs won't recognize.

share|improve this answer
thanks luke, i'll try it out – Jon Jan 31 '11 at 23:07

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