I erased the harddrive partiton from my mac..

Joined
Sep 24, 2011
Messages
5
Reaction score
0
Points
1
I just bought a new macbook pro, with OS X Lion installed, and I wanted to go back to snow leopard. So I restarted, held down ALT, and went into Disk Utility and erased the hard drive partition, so I could restart and install snow leopard. Somehow, when I restarted, it made the snow leopard install cd its only partition, only with 4gb of 500gb. And its locked. I managed to get the cd out, but now I cant remove the locked partition, or make a second partition. An error comes up saying "Couldn´t unmount disk."
If someone could try to help me with this, that would be great. Thank you.
 

bobtomay

,
Retired Staff
Joined
Dec 22, 2006
Messages
26,561
Reaction score
677
Points
113
Location
Texas, where else?
Your Mac's Specs
15" MBP '06 2.33 C2D 4GB 10.7; 13" MBA '14 1.8 i7 8GB 10.11; 21" iMac '13 2.9 i5 8GB 10.11; 6S
Re-boot the MBP while holding the option key. Select Recovery HD and reinstall Lion.
 

bobtomay

,
Retired Staff
Joined
Dec 22, 2006
Messages
26,561
Reaction score
677
Points
113
Location
Texas, where else?
Your Mac's Specs
15" MBP '06 2.33 C2D 4GB 10.7; 13" MBA '14 1.8 i7 8GB 10.11; 21" iMac '13 2.9 i5 8GB 10.11; 6S
Give this a shot - reboot and select the Recovery HD partition.

This time choose Disk Utility.

Select the top hard drive - not the partition under it and not the disk1 (that's the Recovery HD partition).

Head for the Partition tab - under Partition Layout - set it to 1 Partition.
Give it a name - the Format should already read Mac OS Extended (Journaled)
Click Apply

Once done with the format - reboot and try the install again.
I've not installed from there yet - you might check the apple menu before you reboot and see if it's got the option for the install there.
 
OP
P
Joined
Sep 24, 2011
Messages
5
Reaction score
0
Points
1
Give this a shot - reboot and select the Recovery HD partition.

This time choose Disk Utility.

Select the top hard drive - not the partition under it and not the disk1 (that's the Recovery HD partition).

Head for the Partition tab - under Partition Layout - set it to 1 Partition.
Give it a name - the Format should already read Mac OS Extended (Journaled)
Click Apply

Once done with the format - reboot and try the install again.
I've not installed from there yet - you might check the apple menu before you reboot and see if it's got the option for the install there.

I even tried this, I get the error that say "Could not unmount Install Mac OS X"
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,247
Reaction score
1,834
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
You can not install Snow Leopard on a new MacBook Pro that came pre-installed with Lion. You should have asked us first or called Apple support before you attempted it. OK. Too late, let's see if we can recover....

Reboot the MBP but hold down the OPTION key as soon as you hear the POST chime. Choose to boot from your Recovery Partition. Once in recovery, select Disk Utility. Select the "Partition" tab and highlight the 4 GB partition. Press the small minus (-) button at the bottom and select apply. Make sure the entire hard drive is shown as one partition. (The Recovery partition is hidden) If it is, get out of Disk Utility and then select reinstall Lion.

Make sure you are connected to the internet. Lion will be downloaded from Apple and reinstalled on your machine. Take note that if you had any data on the drive it will be lost - so make sure you backup anything you wish to keep before doing the above.
 
OP
P
Joined
Sep 24, 2011
Messages
5
Reaction score
0
Points
1
You can not install Snow Leopard on a new MacBook Pro that came pre-installed with Lion. You should have asked us first or called Apple support before you attempted it. OK. Too late, let's see if we can recover....

Reboot the MBP but hold down the OPTION key as soon as you hear the POST chime. Choose to boot from your Recovery Partition. Once in recovery, select Disk Utility. Select the "Partition" tab and highlight the 4 GB partition. Press the small minus (-) button at the bottom and select apply. Make sure the entire hard drive is shown as one partition. (The Recovery partition is hidden) If it is, get out of Disk Utility and then select reinstall Lion.

Make sure you are connected to the internet. Lion will be downloaded from Apple and reinstalled on your machine. Take note that if you had any data on the drive it will be lost - so make sure you backup anything you wish to keep before doing the above.

I tried this, but I got an error saying: "Couldn´t unmount disk". I think the partition is locked somehow. I tried unmounting and everything, but same error occured.
Any other ideas? :)
 
Joined
Nov 28, 2007
Messages
25,564
Reaction score
486
Points
83
Location
Blue Mountains NSW Australia
Your Mac's Specs
Silver M1 iMac 512/16/8/8 macOS 11.6
No. You got the best advice free. Why would you want to erase Lion for an older slower operating system?
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,247
Reaction score
1,834
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
I tried this, but I got an error saying: "Couldn´t unmount disk". I think the partition is locked somehow. I tried unmounting and everything, but same error occured. Any other ideas? :)

I don't have any other ideas other than take your new MBP to the nearest Apple store and have the technicians (genius) reinstall Lion for you. Make sure you call first for an appointment.
 

bobtomay

,
Retired Staff
Joined
Dec 22, 2006
Messages
26,561
Reaction score
677
Points
113
Location
Texas, where else?
Your Mac's Specs
15" MBP '06 2.33 C2D 4GB 10.7; 13" MBA '14 1.8 i7 8GB 10.11; 21" iMac '13 2.9 i5 8GB 10.11; 6S
Note: Merged duplicate threads
 
OP
P
Joined
Sep 24, 2011
Messages
5
Reaction score
0
Points
1
I don't have any other ideas other than take your new MBP to the nearest Apple store and have the technicians (genius) reinstall Lion for you. Make sure you call first for an appointment.

Thanks you anyways, Ill just bring it back, and hope they can help :)
 

Shop Amazon


Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Top