Convert SSD from MBR to GPT on Lenovo T450S laptop

jm44jg39 · 17 Feb 2021

Hi, my grandson recently sent me his LENOVO T450S laptop that would not boot. I quickly realized the spinner HDD was bad and installed a 120 GB Toshiba SSD. Since this was a new SSD to the T450S I used the "Media Creation Tool" to down load and install Windows 10 Pro and this was activated. The install of Win 10 went fine and booted right up. I then discovered that the T450S had a small 15 GB M.2 SSD. The W10 installed on the new SSD as a MBR drive. The 15 GB is also a MBR SSD with a "System Reserved" partition. 
I would like to change the Toshiba SSD to a GPT as well as the 15 GB M.2 SSD. I don't care if all data/my files are deleted as I can install Win 10 again using the Media Creation Tool. I attempted this conversion using the Aomei Partition software but was warned that doing this MBR to GPT would make the T450S unbootable. 
Is there a solution to this situation? 
 
PS 
All drivers and Windows 10 and the BIOS have been updated. And I have made a Reflect image backup on a USB. I also have backed to a separate USB any misc. files.

Megahertz · 17 Feb 2021

To boot as UEFI-GPT, BIOS must be UEFI compatible and OS must be 64 bits.
You have basically 2 alternatives.

- Convert the existing Legacy-MBR into UEFI-GPT using mbr2gpt

- Reinstall Windows as UEFI-GPT
Reset BIOS or load defaults.
Set Disk mode to AHCI, not RAID
Disable fast boot and secure boot (you can turn it on after installation)

Windows can be installed in two ways: Legacy-MBR or UEFI-GPT
To install as Legacy-MBR you must boot the installation drive as Legacy
To install as UEFI-GPT you must boot the installation drive as UEFI.

During POST, F12 or (Fn+F12) to launch the boot menu. You will see two options for the USB drive. USB UEFI (Name) and USB (Name). Select USB UEFI (Name).
Go to install and delete ALL partitions on the SSD till you have one and only one unallocated space and then proceed.
If you don't want to use MS account, don't enable updates or connect to the internet during installation.

Chrysalis · 17 Feb 2021

You can create the partition inside windows, and choose GPT.

Also if you install windows whilst booting in UEFI mode, it will create GPT by default (providing you make a partition in the installer part of the setup).

Megahertz · 17 Feb 2021

To understand better what you have, please post a Disk Manager image (full window, expanded columns).
How to Post a Screenshot of Disk Management

The M.2 drive was used as a disk cache. With a SSD it is quite useless.

There is a new BIOS for the T450. Suggest you update it.
BIOS Update (Utility & Bootable CD) for Windows 10 (64-bit), 8.1, 7 (32-bit, 64-bit) - ThinkPad T450, T450s - Lenovo Support GB

jm44jg39 · 17 Feb 2021

Ghot · 17 Feb 2021

@jm44jg39

Is there some particular reason you want to switch to GPT?
On that small of an SSD, there is really no need to switch to GPT anyway.

Modern BIOSes have two settings... Legacy and UEFI.
When set for Legacy, Windows will create an MBR disk. When set to UEFI, it will create a GPT disk.

Your BIOS is probably set to Legacy, or only allows Legacy.
You need to examine the CSM section of the Boot tab in the BIOS, to find out.

Convert Windows 10 from Legacy BIOS to UEFI without Data Loss

/edit

By way of example, this is my computer... see the info in the RED squares.

Convert SSD from MBR to GPT on Lenovo T450S laptop-image1.png

jm44jg39 · 17 Feb 2021

Thanks for the help. I will do later as I’m in cold Texas and I keep loosing power and my wi fi. I’m now on cell phone. I see where I messed up with the screen shot. Will re do and up load later.
I would like to be using UEIF for faster performance and ability to create more patroons on ssd.

Ghot · 17 Feb 2021

jm44jg39 said:

Thanks for the help. I will do later as I’m in cold Texas and I keep loosing power and my wi fi. I’m now on cell phone. I see where I messed up with the screen shot. Will re do and up load later.
I would like to be using UEIF for faster performance and ability to create more patroons on ssd.

You can create 4 on your 120GB SSD with MBR partition. If it was a larger SSD, I would understand.
As for speed, there is no difference between MBR and GPT.

MBR vs GPT: Which One Is Better for You?

Where it says: "Firmware interface support"... that is referring to the Legacy/UEFI setting in the BIOS.
Very old BIOSes will ONLY allow Legacy.

Side Note: If your drive, Windows or Storage, is larger than 2TB, then it must be GPT.

SIW2 · 17 Feb 2021

Important:
If the computer is equipped with both a harddiskdrive and an M.2 solid-statedrive,do not use the M.2 solid-statedrive as a bootable device.The M.2 solid-state drive is designed and developed for “cache” function purpose only.

Page 19
https://download.lenovo.com/pccbbs/m...sp40a27225.pdf

https://psref.lenovo.com/syspool/Sys...T450s_Spec.PDF

Chrysalis · 18 Feb 2021

The main benefit of UEFI is secure boot and large partitions. If you dont care for that then MBR will be fine.