Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Recently, Apple released OS X Lion and when I tried to install it on my mac machine, it gave me an error saying my machine partition table is not using GUID partition table. Instead, the current partition is using MBR and OS X Lion can only be install on GUID partition.

Also, I installed Windows 7 on the same machine. Is there any way that I can backup both the operating system like an image so I don't have to install fresh copy of them and other software apps installed on it because I have installed very big applications on each OS (like on Windows I have Visual Studio 2010, SQL Server 208 R2 etc).

So if I remove them and install both as fresh copy (which is a requirement because I am converting MBR to GUID partition and for this I have to re-create and format whole hard drive) it'll take alot of time and it'll disrupt my work too.

How can I make my life easier?

share|improve this question
up vote 1 down vote accepted

for both OS image can be made up which has all the settings, but when considering Windows OS image won't be of no good as the partition scheme has been changed ... so for windows you have to do the installation of OS and all the application you required again ...

or you can try loading an image using VMWare or any other virtual OS running software

and here is the few tutorial i looked in before doing this:

and to convert from MBR to GUID, do this in mac os x:

To partition disks other than your startup disk, from the Finder click Go, and select Utilities. In the Utilities folder, double-click Disk Utility. Once Disk Utility is open, do the following:

  • In the left column, click the drive you would like to initialize or partition.

  • To the right, click the Partition tab.

  • In the drop-down menu under "Partition Layout" or "Volume Scheme:", choose the number of partitions you want to create during the initializing process. For a basic installation of Mac OS X, you need at least one partition.

  • Adjust partition sizes by dragging the handles that represent the partition borders.

  • Click each partition to adjust its properties. Under "Partition Information" or "Volume Information", choose the format you would like to use. You should usually use Mac OS Extended (Journaled). If you need to access the partition from Windows computers, however, choose MS-DOS.

  • Click Options... to change the partition scheme. You may need to change this if the disk is meant to be used with Windows computers, or as a startup disk for a Mac with a different architecture. Intel Macs require the GUID Partition Table for their startup disks, while PowerPC Macs use Apple Partition Map. If you need to use the disk with Windows, particularly as a startup disk, choose Master Boot Record. After selecting a scheme, click OK.

  • When you're finished making changes, click Apply or Partition button.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.