Convert Windows 7 64bit BOOT Disk MBR to GPT Disk – NO DATA LOSS
Converting a BOOTABLE MBR to GPT Using Linux Parted Magic
Please read the notes below for important prerequisites and Requirements
This is how to convert a Windows 7 64bit MBR installation to a GPT Disk
Why convert from MBR to GPT? -This is becoming the new standard
Faster Boot-up – debatable
Multiple Redundant partition tables – ads reliability and security against disk damage
If you need more than 4 primary volumes on one disk
Supports HDD greater than 2TiB
64 bit CPU & O/S
GPT or GUID Partitioning Table Globally Unique IDentifiers Partitioning Table is a hard disk partitioning standard. You can’t have two different partitioning systems on one hard disk; you either divide up the disk one way or the other but not both.
DO NOT TRY MBR TO GPT conversion in a Windows system. It will lead to a BSOD Blue Screen of Death due to partmgr.sys . Do the conversion in a Linux system only.
Prerequisites:
Note 1: Windows requires a UEFI 2.x x86_64bit firmware, it will not work in EFI 1.1 firmware and it will not work in 32-bit UEFI firmware not even 32-bit UEFI 2.x firmware.
Note 2: Only 64-bit Vista Sp1 & Win7 Sp1 can boot from GPT disk, provided they boot using UEFI firmware, not BIOS firmware. 32-bit Windows XP does not have support to use GPT disks even as DATA disks, 32-bit Win XP has absolutely no GPT support.
Note 3: Installation Disc or ISO of your Installed Operating System – Windows Vista SP1+ x64 disc or Windows 7 SP1 x64 disc — needed for files and recovery options, very important to recreate BCD — borrow someone’s disc if you have to.
Note 4: If you have any Logical/Extended partitions on your HDD, it is best to convert these to Primary partitions to eliminate any partition gaps during the MBR to GPT conversion. Then verify your OS still boots after you’re done.
Requirements:
UEFI 2.x x86_64bit firmware either in the motherboard itself or booting from a partition or through a memdisk or through a USB pen drive — NOT x86 32-bit and NOT EFI 1.1 — both are not supported.
Any Linux rescue distro with GPT fdisk / gdisk — Parted Magic or any GPT-aware portioning tool. I used Parted Magic 2014-4-28
USB Thumbdrive of at least 250mb, formatted Fat32
Very important, First create a backup image of your HDD ! Optionally you may want to consider defragmenting your drive prior to backing it up.
1. Copy Windows Boot Files to USB thumbdrive. To avoid possible version issues, it is best to get these files from the install disks rather than the installed O/S, however either in theory should work. I used them from the install disks. After the disk is converted to GPT, these files will be placed in the EFI partition.
The windows boot files are available in 2 places:1. on the hard drive, and 2. on the install DVD.
To retrieve from your installed OS HDD you will need to set your system to “Show Hidden Files”:
Open an explorer window and press “Alt” to bring up the menu.
Go to: Tools then Folder Options
Select the View tab.
Select “Show hidden files, folders, and drives”. Apply
See Video for Linux Repair
After Linux repair:
Repair the Windows 7 Startup Files
Reboot the computer using your Windows 7 Sp1 x64 Setup disk. Borrow one if you have to. Just be sure it’s a 64-bit version of Windows 7; the 32-bit version doesn’t support UEFI.
*** Be sure to boot the disk in UEFI/GPT mode. On my Asus the steps are as follows:
1. Press “Esc” to enter the Startup Menu.
2. Press “F8″ to enter the Boot Menu.
3. Select your DVD from the UEFI Boot Sources list. Mine is called “UEFI: ATAPI iHAS224 B”
After the disk boots, choose your language and keyboard and press “Next”. Additionally you should see a screen when booting from the DVD that says:
“Windows EMS enabled”
Select your language and select next, then the INSTALL screen appears, hit Shift + F10 to open a command prompt. Determine which drive letter is your Windows installation usually C: then from X:SOURCES, run:
BCDBOOT driveletter:WINDOWS /V Normally C: this ads boot files to the HDD
WPEUTIL REBOOT this reboots the machine
You should get a successful confirmation message. Now you should be able to reboot into your Windows system.
Note: Be sure your UEFI Bios boot is set to have the Windows Boot Manager option listed first.
……..
If you get an error message that says:
This version of System Recovery Options is not compatible with the version of
Windows you are trying to repair. Try using a recovery disc that is compatible
with this version of Windows.
If so, use the boot files from the Windows 7 Setup DVD, not from your computer. The boot files from the Install Disk will be compatible with the Booted DVD, OR you didn’t boot from the UEFI menu correctly.
If everything is working properly, you will get the following message:
Windows found problems with your computer’s startup options. Do you want to apply
repairs and restart the computer?
how to repair windows 7
