Recently, Apple has released the fifth beta for iOS 7, Many people have downloaded or installed iOS 7 beta firmware, then you must know the .dmg format (Disk Copy Image File)
Apple always release iOS beta as a dmg extension to developers, which facilitates developers to test apps with XCode on Mac environment.
So if you find a file with the .dmg extension, then indicates that it is a Mac OS X Disk Image file. The Mac users can open .dmg files on Mac OS 9 and OS X, using Apple Disk Copy. It should be in the Applications (Mac OS 9)/Utilities folder. But if you are a Windows user, you will be in trouble, since Windows can not recognize dmg format by default. You must resort to third-party software.
DMG Extractor is such a software allows you to extract / unzip the dmg file to get the contents you want. If you downloaded the iOS 7 beta firmware with dmg extension, then you need to extract a ipsw file in which for iTunes restoring.
Download DMG Extractor 1.1.7 for Windows
Note: Windows XP users will need to install the .NET 2 framework if they haven’t already
DMG Extractor works all dmg files: Raw, Zlib, Bzip2, and Zero block type DMG files.
How to Extract IPSW file from iOS 7 beta DMG file on a Windows PC
Step 1: Install the DMG Extractor (dmge-lastest.exe) you downloaded from the above link.
Step 2: Download the iOS 7 beta dmg file if you haven’t already.
Step 3: Find out the dmg file you downloaded, such as (ios_7_beta_5__iphone_5_model_a1429__11a4449a.dmg) You will see a clear “DMG” word on the file icon, which means the file can be opened with DMG Extractor by default
Step 4: Double-click the dmg file, a window will pop up, shows as below, to find out ipsw file you need to click “iOS 7 beta 5 – iPhone 5 (Model A1429) – 11a4449a” folder. Then you will see the “iPhone5.2_7.0_11A4449a_Restore.ipsw” file, which is what we wanted
Step 5: Select the ipsw file, click Extract -> Selected files to … then select a folder for the ipsw file, we recommend that you extract it to your desktop, so easy you find.
A window will pop up, which prompts you to
“In the Free edition, you can only extract up to 5 files at any one time.
Please register the Home edition to access all our great features. ”
Because we downloaded the free version, just click the Continue button to ignore it. Then the extract work will begin,soon completed.
Step 6: Now launch iTunes and press “Shift” key on your keyboard and the “Check for Update” button that appears on your screen, then select the iOS 7 IPSW file you extracted from the DMG for updating.