Can't install MAC OS X Lion - Macintosh HD "This disk cannot be used to start up your computer."

I had the same issue with the Macintosh HD being grayed out, saying it was used for time machine backups. No resizing or partioning is required. The problem is caused by an empty time machine file in the macintosh hard drive folder. Go to finder open up your hard drive and look for a file called Backups.backupdb. Delete the file and relaunch the installer.

OK, I finally have Lion installed on the MBP. (I'm not going to deal with installing it on the iMac for a few weeks.) What I had to do was do a clean install of Snow Leopard, merging my partitions in the process, updating Snow Leopard and then Lion installed without any difficulty. Hope this helps someone.

I am getting the "This disc cannot be used to start up your computer" error.

I have tried searching for the "Backups.backupdb" file on my computer, but it cannot be found.

When I try resizing my partition, I receive the following error: "MediaKit reports partition (map) too small".

I have tried the Verify/Repair Disk and Verify Disk Permissions/Repair Disk Permissions tools.

I'm running a brand new (2 week old) 27" iMac. I have 1.45 TB of available space on my HD.

I tried calling tech support, but they just told me that I would need to wipe my HD, reinstall Snow Leapard, download Lion again, then try to install it. I'm sorry, but that's nuts.

Can anyone please help? 😟

Thank you, thank you. Worked for me as well. Partition change did not work but deleting this backup file did the trick.

Had the same issue. This is what I did,

1. removed rEFIt

2. delete non-mac partition

3. resize SL partition to occupy full HD

Lion is happy now.

Worked for me, thanks!

I have had the same issue. Im on a MacPro with 4 disks. Lion refused to upgrade/install on the "Mac" startup disk, allowing me only to select a disk dedicated to my Fusion "Windows" files. Then when I re-started to Lion NOTHING carried over.

No .Me account information, mail, contacts, bookmarks, applications, media, documents, folders PLUS I can not "see" and of the three other drives on my desktop to access those disks -- its like they aren't there.

I was able to go into system preferences and change the startup disk to my 10.6 Mac disk (which I am working from right now). The problem is somehow in the conversion my .Me account got junked up and my calendar is off (and Lord knows what else that I have not discovered.

I have to say this is the first time I have truly been disappointed with an Apple product or experience. I can't believe that they released this upgrade without adequate testing. This is acctually worse than a Windows install/upgrade.

I have an appointment tomorrow -- I am praying that their CS reps are knowledgeable and fluent English speakers.

I have the message listed above: "This disk cannot be used to start up your computer." I have tried all suggestions listed above.

• I do not have rEFIt installed and double checked by looking in /Library/Startup Items.
• I have resized my Macintosh HD partition hit apply. Checked Lion installer app, no change. Resized partition back to full size, no change.
• Confirmed partition map is GUID
• Created new partition with current mapping and this partition failed to mount or erase properly.

With this last step I decided to image the drive with disk utility. Completely repartition and reformat. Than I am going to restore from my image and attempt the install again.

Will post update if successful.

I tried resizing my Mac OS X partition, but the error "Mediakit reports no such partition" came up. I tried deleting my Linux Swap partition, and it appears to work, but the partition doesn't leave the Disk Utility screen. I tried deleted my Linux partition, but the same Mediakit error appears. I tried deleted both of these partitions with Disk Utility running from my Snow Leopard CD, and the same things happened. I deleted rEFIt. That didn't work. I repaired and verifired my disk permissions. That didn't work. I am running OS X 10.6.8. The "Partition Map Scheme" is GUID Partition Table. I tried deleting my partitions using Boot Camp Assistant, but it shows me a screen about needing Windows Software with two options. With both options, I get the error "The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows." Basically, every solution I am trying is impossible. Does anyone have any advice for how to avoid these errors? Thanks!

Greg

I'm having the same problem. I cleaned up all my disk partition info (I had refit plus linux at one point) and my disk now looks like:

However, I still get the dreaded "The disk cannot be used to start up your computer" error.

Any ideas?

Davve

You could try opening Terminal and using the command:

defaults write com.apple.diskutility DUDebugMenuEnabled 1

Then selct Disk Utility >Debug>Show all partitions.

Maybe something will show up?

What format is your HD it should be Mac OS extended. The volume may need repairing....

Try Disk Utility

1. Start from your Mac OS X Install disc: Insert the installation disc, then restart the computer while holding the C key.
2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)
   Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.
3. Click the First Aid tab.
4. Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
5. Select your Mac OS X volume.
6. Click Repair. Disk Utility checks and repairs the disk.

Tip: Always start up your computer from an Install or Restore disc when using Disk Utility to verify or repair your startup volume. Otherwise, you might see some disk error messages.

Use fsck if necessary

fsck is a command-line utility that may be able to verify and repair a disk. If you can successfully start up in Safe Mode or use Disk Utility while started up from a disc, you don't need to use fsck. Here are some situations in whichfsck may be necessary.

• Your Mac OS X disc isn't available.
• Your optical drive isn't available.
• You can't start with a Safe Boot by holding the Shift key during start up.

To use fsck, you must run it from the command line. Unlike using your mouse pointer to open an application to do something, you'll need to type a text command at the prompt (#) to tell fsck what to do. The Terminal application (/Applications/Utilities) and single-user mode are two examples of command-line interfaces in which you can type such commands. To use fsck:

1. Start up your computer in single-user mode to reach the command line. Enter single user mode by holding Apple key + S at system startup.
   Note: If necessary, perform a forced restart as described in the Emergency Troubleshooting Handbook that came with your computer. On desktop computers, you can do this by pressing the reset/interrupt button (if there is one) or holding down the power button for several seconds. On portable computers, simultaneously press the Command-Control-power keys. If your portable computer doesn't restart with this method, you may need toreset the Power Manager.
2. At the command-line prompt type:
   fsck -fy
   
3. Press Return. fsck will go through five "phases" and then return information about your disk's use and fragmentation. Once it finishes, it'll display this message if no issue is found:
   

   ** The volume (name_of_volume) appears to be OK

   If fsck found issues and has altered, repaired, or fixed anything, it will display this message:
   

   ***** FILE SYSTEM WAS MODIFIED *****

   Important: If this message appears, repeat the fsck command you typed in step 2 until fsck tells you that your volume appears to be OK (first-pass repairs may uncover additional issues, so this is a normal thing to do).
4. When fsck reports that your volume is OK, type reboot at the prompt and then press Return.

Your computer should start up normally and allow you to log in

Now try and partition the drive again

Good Luck!

Finally got it installed on my iMac.

I tried adjusting the partition size and reverting it back to the original size so I could 'Apply', that didn't work.

In the end - I had to delete my bootcamp partition. Fortunately I also have VMWare Fusion so was able to import it as a virtual partition so I can still run Windows if I need to (to be perfectly honest, I always regretted wasting 60gb on the Bootcamp partition anyway since I use it no-where NEAR as often as I thought I would...

Up and running now, but very infuriating.. Can't understand why it wouldn't install on the iMac with my Bootcamp partition when it installed no problem on my MacBook Pro which has an almost identical Bootcamp config.

J

I'm going to be severly ****** if the only solution is to delete my linux partitions.

This might be the last straw on whether I dump OSX for linux completely.

it is a problem with your bootcamp. the following will give your a hand

http://support.apple.com/kb/HT4649