Although Guid Partition Table (GPT) is a new disk layout and has some advantages,
there are still some situations need converting Guid Partition Table (GPT) to Master
Boot Record (MBR). Let’s look at the following two examples from computer forum:
1. I have a Lenovo U510 and it came installed with Windows 8, but I want to install
Windows 7 instead. The Windows 7 installation would not let me install it because
the drive is formatted to GPT (Both 24GB SSD and 750GB hard drive). What should I
do?
2. I wiped my Windows 8 thinking I could install Windows 7 x86 but I can’t because
the disk is GPT. I need to convert to MBR. Is there a tool to do that?
3. When I boot my computer up, it’s unable to boot from the hard drive, as the BIOS
just says can’t boot to hard drive. But when I take the drive out and put it into
another computer (XP, 32 bit) to try to recover files, it doesn’t show up in Windows
explorer, but shows up as a GPT protective drive (healthy) in administrative tools
> storage utility, with no drive letter but just a blank next to the hard drive
icon.
The second example asked a question “Is there a tool to do that?” The answer is yes.
A professional partition software named AOMEI Partition Assistant is able to do this
without data loss.
Method 1
Download, install and run AOMEI Partition Assistant
Professional Edition. Right click Disk 1 and select “Convert to MBR Disk”.

Click “OK” in the pop-up window if you are sure.

Back to the main interface, you can see the pending operating. Click “Apply” and
“Proceed” in the pop-up window to start converting.

Method 1 only needs few steps, Simple, right? Next is method 2.
Method 2:
This method is converting Guid Partition Table(GPT) to Master Boot Record(MBR) via
command line.
Right click Command Prompt, and then click run as administrator,
Type list disk. Make note of the disk number you want to delete.
Type select disk [number]
Type clean.
Type convert mbr.
This method request the disk is empty and contains no volumes, so you should delete
and clean first. I suggest you back up volumes by using backup freeware.
Method 3:
This method is converting Guid Partition Table (GPT) to Master Boot Record (MBR) with
Windows disk management.
Log on as administrator.
Right-click Computer and select Manage.
Select Disk Management from the left pane under Storage category.
On the right pane, ensure that the hard disk drive on which you want to
reinstall Windows has no partition. (If it has, delete it first. Otherwise
Convert to MBR option would be grayed out and would be disabled)

This method also request the disk is empty and contains no partitions. I don’t think
it is a ideal method.
These methods are compared, and the method 1 is the best. Biggest advantage is that
don’t mind a disk is empty or not. AOMEI Partition Assistant is professional and
safe.
It has other amazing features such as migrate
OS to SDD, Windows 8 To Go Creator if you have
no Windows 8 Enterprise Edition, you can also create a portable Windows 8. For more
information, please visit /manual.html. Thanks for
reading.