Hi, in this video, I'll be showing you how
to convert your legacy installation of Windows
into UEFI mode using tools provided by Microsoft.
So, let's begin.
Before proceeding further, let's take a look
at the various drives that we have on this
computer.
I'll click on explorer then go to 'This PC'.
As you can see here, I've four different drives.
Drive C, E and F. I also have a drive G which
is basically an external drive attached via
a USB cable which is of size half a terabyte.
The partition in which the operating system
is installed is of size 24.5GB.
Now it is important to know the size here,
because I'll be referring to the sizes later
on in this video.
To get a better understanding of the disk
layout of the various disks attached to this
computer, we'll now open the program: Disk
Management.
As you can see, both the disks are visible
here.
The first partition is the system reserved
partition, this was not visible in the explorer
because it was hidden and wasn't assigned
any drive letter; followed by C, E and F and
of course, the external partition G.
We can also see the various drive sizes and
letters and labels assigned to each partition.
Now, this is a Windows installation in Legacy
mode, which is why, the partitioning scheme
used by disk 0 is MBR.
That is why on right click, we see the option
to convert to GPT.
We'll see that this option changes to something
else after the procedure.
Now, we'll take a look at disk layout from
the perspective of another tool called 'diskpart'.
The first thing we are going to do here is
to list the available disks.
Disk 0, and Disk 1.
Let's also look at the disk management tool
side by side.
Let's compare the sizes to confirm the two
disks that we see in the output of diskpart.
512GB for disk 1 and 60GB for disk 0.
It's important to note here that the dynamic
and GPT columns don't have any marker.
You might have a marker for the external drive.
But, we are only concerned about the drive
that we are going to convert today.
Disk 0 is the drive that we are concerned
about and it should not have any marker on
the dynamic or GPT columns.
Now we'll look at the partitions on the first
disk.
As you can see here, there are four primary
partitions.
This corresponds to what we see in the disk
management tool.
Now the problem here is that the MBR2GPT tool
that we are going to use here to convert this
installation does not work with 4 primary
partitions.
It requires at most 3 primary partitions.
So now we'll have to decide to delete one
of these partitions so that the tool that
we are going to use will work.
We can see that the 4th partition, the 'Movies'
one, is empty.
I had already backed up all the data.
So, I'll just delete it and reclaim the space.
So that we have 3 primary partitions and we
can proceed with the method that I am going
to follow in this video.
So, let's delete the 4th partition.
You can choose to delete any other primary
partition (as long as it's not the one in
which OS is installed); I'm just using the
4th one for convenience and remember, always
make sure to make backups.
Now that we have deleted the 4th partition,
we'll reclaim the space into the third partition.
Now that I've grown the D partition in size,
let's confirm that it has indeed grown in
capacity in the explorer and inside diskpart.
We can see here that the new size has added
20GB of more space.
As you can see the 4th partition is now gone
and the third partition hash increased in
size.
Let's close diskpart now.
Before we proceed further, let us check which
mode we have booted Windows in.
To do that, we will open the system information
application and observe the system summary.
In the 'BIOS mode' field, we'll see the value
is 'Legacy'.
It might be the case that the version of Windows
you are using is old and this summary doesn't
have this field.
And that's okay.
There are other ways to confirm like the blank
GPT column we saw before (for the disk we
have booted in)?
For the next step of this video, we'll require
a Windows installation or recovery or WinPE
media.
There are multiple ways to create one.
But for now, I will assume you have access
to one and it can be a disk or a USB drive.
For this video, I have attached one such media,
as we can see in the explorer.
Alright, so now it's time to shut down the
computer and proceed with the next step of
actually converting the installation.
Let's boot the Windows recovery or installation
media.
The UEFI/BIOS settings on your machine might
look different as it differs from manufacturer
to manufacturer.
Once booted, you'll be either be greeted by
a command prompt window, or a dialog box such
as this, or a group of options.
We simply need to launch the command prompt.
One shortcut to do that is to press shift
+ f10 on the keyboard.
If that is not feasible, find another way
to open the command prompt window.
Here, we'll click on next, repair, troubleshoot,
finally followed by Command Prompt.
Let's check which mode we have booted the
media in.
First, we'll update the boot information.
Then, we will query the registry.
0x2 corresponds to UEFI and 0x1 corresponds
to Legacy.
In this case, we have booted up in the UEFI
mode.
Even if you see 0x1 here, it is okay.
It is not necessary to boot in UEFI mode.
But it would be my recommendation to do so,
because some UEFI implementations are buggy
and don't recognize changes made to boot entries
in Legacy mode.
Let's proceed with the next part of the video.
Let us fire up diskpart and look at the disks.
It is important to verify the disk number.
Disk 0, Disk 1.
Disk 0 is of size 60GB and Disk 1 is of size
512GB.
Also note that the Dynamic and GPT columns
are empty for Disk 0.
If the size of both of your disks is same,
you might want to further look at the partitions
to verify which disk you want are actually
interested in converting.
Let us list down the partitions in the first
disk.
We can see that this disk contains three partitions
and one of them is of size 24GB, which corresponds
to the size of the partition in which I had
Windows installed in.
Now, I am confident that Disk 0 is the disk
that I want to meddle with.
Let us close diskpart.
Now, we will take a look a the MBR2GPT tool.
Let's list down the various options it supports.
We are interested in three parameters.
Validation, conversion, and the disk number.
First, we will validate the current disk layout.
Note that we will use the disk number we concluded
in the previous section of this video.
The validation command is completely harmless,
makes no modifications and it should succeed.
If this command does not succeed, please do
not panic.
I will cover two more problematic scenarios
at the end of this video and also show how
to resolve them.
Now, assuming that this command has succeeded,
let us proceed with the actual conversion.
This command is going to change the disk partitioning
layout from MBR to GPT.
For the purpose of this procedure, this command
has to succeed.
Conversion completed successfully.
Now, in most cases, we should be done and
on reboot, Windows should boot in UEFI mode.
However, I'll share a few extra steps which
are entirely optional but should be followed
in case this succeeds, but Windows does not
boot up in UEFI mode.
There should be no harm in following the optional
steps.
Let's proceed further.
Let us open diskpart again.
Let us look at the current disks.
As one can notice, there is a mark under the
GPT column for the first disk, which was not
present before.
This tells us that the current disk partitioning
scheme for Disk 0 is GPT, which is what we
expected to be.
Let's look at the partitions to verify that
everything is intact.
We are again seeing three primary partitions,
which is good.
Let us assign drive letters to a few partitions
for the optional step.
Pick the system partition and assign it the
drive letter B: . Then pick the partition
in which Windows is installed and assign it
the drive letter W: . To verify, let's take
a look at the volume list.
Note that the filesystem type of the system
partition is now FAT32.
Let us exit out of diskpart now.
For the optional step, we'll create certain
boot entries manually.
Be very mindful of the spaces in these commands.
Sometimes they can trip you up!
Boot files successfully created.
All done!
Now we will shutdown this computer and reboot
in UEFI mode.
Let us reboot.
Windows will detect that the boot mode has
changed and will need to reconfigure certain
internals which will take some time.
It may be the case that it will reboot once
or twice in between.
It has rebooted again.
Let's hope that's the final time!
Alright, now, we will open disk management
again, and check for differences compared
to last time.
We will see that the system reserved partition
is now the EFI system partition and the other
two partitions are intact on Disk 0.
We can also see that the 'Convert to GPT Disk'
option has disappeared and now it provides
the option to convert to MBR instead.
This means that the partitioning scheme has
indeed changed.
Disk 1 has also remained intact and no changes
have been made.
Let us open diskpart again and verify.
Let us list the disks.
The market under the GPT column is present
for Disk 0, which proves that everything is
correct and as expected.
Now finally, let's verify that the boot mode
has changed to UEFI.
Under system summary, the BIOS Mode is saying
UEFI.
Yay!
We have finally converted it!
Now I'll talk about two common problems with
the MBR2GPT tool in the remaining part of
the video.
Let us take a look at one of the most common
errors with which the MBR2GPT tool fails.
In this case, it says "Disk layout validation
failed for disk 0".
This means that the disk layout is incompatible
for conversion to GPT.
In most cases, this problem arises when you
have more than 3 primary partitions on the
disk you want to convert.
Let us take a look.
With disk part we can list down the number
of partitions that we have on Disk 0.
As you can see, I have more than 3 primary
partitions on this disk which the MBR2GPT
tool does not like.
If this is the case for you, please boot back
into Windows, backup one of the non-OS partitions
and delete them as shown in the earlier part
of this video.
And then, try to use the MBR2GPT tool again.
Now let us move on to the next common problem.
The second most common error with MBR2GPT
is when it cannot find the OS partition for
Disk 0.
As we can see here.
There could be many reasons which can cause
this problem.
One reason could be due to bad entries in
the boot configuration data.
Let us check for that.
With diskpart, let's find out the partition
in which the OS is installed and the partition
which is the system reserved one.
Bear in mind that not all legacy installations
have the system reserved partition.
In that case, the boot files will most likely
be present in the partition in which the OS
was installed.
In any case, we will check for both.
Let us assign the drive letter W: to the Windows
partition and the drive letter B: to the system
reserved one.
Now, let's take a look inside the Windows
partition.
In my case, there doesn't seem to be any boot
folder inside the Windows partition, so let's
check the system reserved one.
Bingo!
Here is the boot folder.
Now, let's invoke the bcdedit tool and point
it to the boot configuration data store that
we have found and look for any invalid entries.
There can be many hints for a bad entry.
In my case, I see an entry with the word 'unknown'
in it.
The third entry from top points to a partition
which does not exist anymore.
It could be the remnant of a previous installation
or the doing of some bad software.
We'll copy the identifier for this bad entry.
To do that, select it and right click.
Then, we'll point bcdedit to the store again
and ask it to delete the bad boot entry using
the copied identifier.
We can use right click to paste.
It seems to be gone now!
Okay, let's try the MBR2GPT tool again.
Validations succeeds!
