Mac OS 1.6.3 Snow Leopard

Here is the scenario

You go out and buy the new Snow Leopard Mac OS , get home and insert the CD in your Intel based Mac. Everything is looking good until the machine reboots to do the install and you get the message “Mac HD” can’t be used because it doesn’t use the GUID Partition Table Theme.” and then the install stops and wants you to format the partition , which erases all your data.

The reason is the drive you are running 10.4 on may be using the Apple Partition Map (APM) which will not work with 10.6. Usually the APM was used for the older PPC but we have seen it on hard drives that have been replaced or cloned from another machine, esp and older PPC machine.

There is really no good work around we found or a way to straight upgrade the 10.4 machine to 10.6 if it is using APM.

Here is a work around for some you techies and home nerds that should help you get around this issue.

You will need the following:

  • OS 10.6.3 Snow Leopard disk ($29)
  • An external hard drive that is at least the same size as the internal one that can be formatted
  • Time (The clones take awhile to run, but you can set it and forget it pretty much!

What we first did was erase the external hard drive through the Disk Utility on the Mac, and then we partitioned the entire drive using the GUID partition. Make sure you name it similar but just a little different so you know which one is which. When it is done you can rename it to what it was before the upgrade.

We then used Carbon Copy Cloner to clone the 10.4 internal disk to the newly formatted external hard drive with the GUID partition.

Once that was complete we made sure we could boot off the external drive (hold option during boot) and could access the system. Once that was verified we booted off the OS 10.6.3 Snow Leopard DVD and instead of choosing the internal disk to upgrade (since we can’t) , we chose the external hard drive to upgrade.

The upgrade went pretty smooth and once done it booted up with the external drive and now we have a fully functioning 10.6.3 install while still retaining all of our data and settings.

Now what do you do since the internal hard drive is still 10.4 and untouched?

Well, once you verify 100% that the 10.6.3 install is working on the external, just boot to the external disk (may already be on it) and run Carbon Copy Cloner again except this time you are going to first format the internal disk the same way we did the external. Erase and then partion using GUID. Now you clone from external back to internal, boot and verify.

You are all set now. You have all of your settings, data and applications and you are running 10.6.3 Snow Leopard.

I know it sounds like a lot of work, but it really isn’t and we feel it saves some time and trouble in the long run.

Don’t want to do this yourself? Give us a call or just bring down your Mac Laptop or Desktop and we will do it for you!

New England PC and Web

389 West Center St

Suite C

West Bridgewater, Ma 02379


Posted on January 20th, 2011 | filed under Mac, Mac Hardware | Trackback |

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