Question SSD not booting after converting it from MBR to GPT ?

[txt423]

I have recently updated my SSD from MBR to GPT. Then it did not boot on my PC so I went back to MBR and even then it did not load so I am back on GPT. I can see all of my data being safe when attached as external SSD. What can I try to get the OS to load?

 

[SkyNetRising]

Recreate bootloader.

If you convert boot drive from MBR to GPT (or the other direction),
old bootloader is not functional anymore and needs to be recreated.

Boot from windows installation media into command prompt, execute following commands and show screenshot with command output (upload to imgur.com and post link)

diskpart​

list disk​

select disk 0​

list partition​

list volume​

​

Why exactly were you messing with MBR/GPT conversion?
What tools did you use for the conversion?
How many and what model drives are in the system?

 

[Lutfij]

Welcome to the forums, newcomer!

How did you convert from MBR>GPT and back? + Why the multiple conversions? At this point, I'd backup all necessary critical content off the drive and reinstall the OS on your SSD.

 

[SkyNetRising]

I'd backup all necessary critical content off the drive and reinstall the OS on your SSD.

Right.
Use of nuclear weapons just to shoot some pigeons. LOL

 

[txt423]

Recreate bootloader.

If you convert boot drive from MBR to GPT (or the other direction),
old bootloader is not functional anymore and needs to be recreated.

Boot from windows installation media into command prompt, execute following commands and show screenshot with command output (upload to imgur.com and post link)

diskpart​

list disk​

select disk 0​

list partition​

list volume​

​

Why exactly were you messing with MBR/GPT conversion?
What tools did you use for the conversion?
How many and what model drives are in the system?

Thank you so much trying to help!

Getting this.

https://imgur.com/a/14vmgd3

View: https://imgur.com/a/14vmgd3

 

[SkyNetRising]

Thank you so much trying to help!
Getting this.

What version of windows do you have installed?
If you have windows 10, then boot from windows 10 installation media.

In your screenshot it looks like windows 7 installation media.
You can not fix windows 10 using windows 7 installation media.

After you have booted from correct windows installation media, press Shift+F10 , to open command prompt.

 

[txt423]

I converted back to MBR and I was able to get Windows to read the partitions.

Here is what I see:

https://imgur.com/a/oGmWERH

View: https://imgur.com/a/oGmWERH

 

[SkyNetRising]

Execute following:

diskpart​

list disk​

select disk 0​

list partition​

select partition 1​

(select 50MB partition)​

active​

exit​

bcdboot e:\windows /s c:​

​

Last message should be "Boot files created successfully".

 

[txt423]

Thank you.

Here is what I have so far:

https://imgur.com/a/l7I2B3A

View: https://imgur.com/a/l7I2B3A


Error states:

Failure when attempting to copy boot files.

 

[SkyNetRising]

Hmm.
50MB partition might be too small.
Recommended size for bootloader partition is 350-500MB.
Let's try it this way.
If you get any errors, then stop immediately and show screenshot with command output.

​

diskpart​

list disk​

list volume​

select disk 0​

list partition​

select partition 2​

(select 223GB partition)​

shrink desired=500​

create partition primary size=500​

format fs=ntfs quick​

active​

assign letter=H​

exit​

bcdboot E:\windows /s H: /v​

​

What version windows do you have installed in your pc?
Is windows installation media for same windows version as installed?
If they are different, then this will not work.

 

[txt423]

Hmm.
50MB partition might be too small.
Recommended size for bootloader partition is 350-500MB.
Let's try it this way.
If you get any errors, then stop immediately and show screenshot with command output.

​

diskpart​

list disk​

list volume​

select disk 0​

list partition​

select partition 2​

(select 223GB partition)​

shrink desired=500​

create partition primary size=500​

format fs=ntfs quick​

active​

assign letter=H​

exit​

bcdboot E:\windows /s H: /v​

​

What version windows do you have installed in your pc?
Is windows installation media for same windows version as installed?
If they are different, then this will not work.

OMG. Thank you so much for this. From the bottom of my heart. I hope I can pay this much forward in my field of knowledge.

You've saved me weeks worth of work.

 

[undesirable_11]

Hmm.
50MB partition might be too small.
Recommended size for bootloader partition is 350-500MB.
Let's try it this way.
If you get any errors, then stop immediately and show screenshot with command output.

​

diskpart​

list disk​

list volume​

select disk 0​

list partition​

select partition 2​

(select 223GB partition)​

shrink desired=500​

create partition primary size=500​

format fs=ntfs quick​

active​

assign letter=H​

exit​

bcdboot E:\windows /s H: /v​

​

What version windows do you have installed in your pc?
Is windows installation media for same windows version as installed?
If they are different, then this will not work.

I created an account in here just to say THANKS for this solution. I was starting to lose my mind with my PC not booting. I agree with a comment above that says that these tutorials for converting MBR to GPT using third party software absolutely do not tell you that you need a bigger partition to boot Windows. Lesson learned, thanks again!