Hi!

So, I have an external 4 TB hard disk I needed to format, and I did it wrong. Now it only shows 2 TB. For what I read in the internet, I have to convert it to GPT.

Could somebody tell me what program I should use to do it?

Thank you.

https://learn.microsoft.com/en-us/windows/deployment/mbr-to-gpt

Edit: changed link to English version

If you’re on a Windows machine, can’t you just use the built-in Disk Management tool? You can open it by typing diskmgmt.msc in the command prompt. Then, if you right-click the drive you want to convert, you should see the option to switch it to GPT.

I tried the diskmgmt.msc tool, but it doesn´t work. I deleted the 2TB partition, but I can´t or I don´t know how to put both partitions toguether.


EDIT:
I can´t make MBR2GPT.EXE run. I tried to do it as an administrator but it does nothing.

Can you reformat it, or does it have data you can't lose?

1. Move the data out of the drive.
2. Search for "Computer management" and open it as an administrator
3. Under computer management you should find Disk Management.
4. Delete any partitions you have there (right click on the partition(s)).
5. Right-click on the left column on the disk with no partitions, and there should be an option to change it from MBR to GPT.
6. Create a partition (or partitions) and format them and assign them drive letters and whatever you want to do.
7. Copy your data back.
8. Install Linux.

There, simple as a pimple. You'll thank me later.

Ps. I have no idea what you mean by "put both partitions together". What "both partitions"? Didn't you just say you deleted the partition on that disk? Or then I am misunderstanding what you are trying to do. If you don't have any data on that external disk you need to save, delete all partitions that you see on that disk, and then create one or more partitions of your choosing, AFTER you have converted the disk to GPT.

Just be sure you don't go deleting partitions on the other disks of course, use common sense.

Ok, my bad. I wasn´t clicking on the leftmost square where it said "disco 1". I was clicking on the partitions all the time.

Now I feel a bit embarrassed. XD


Now I have full access to the hard disk. Thank you.

Perhaps that disk have been used to install Windows and that will create some partitions, like the boot and recovery partitions. You can delete them all and format as a single partition.

If you have some data, delete all the other partitions and right click "expand volume".

BTW, a easier way to access disk management tool is to right click on the Windows start up button.

Edit: check image. Under no circunstance mess with your Windows install disk. Unlike other tools, it's very easy to crap the Windows install on diskmgmt

Try this:-

1. Back everything up first! Also unplug any other external drives other than the one you're trying to change.

2. Right-click on "Comand Prompt", select "Run as Administrator"

3. Type diskpart

4. Type List Disk

5. Type Select Disk x (where x is the number of the disk you want converted as List Disk displays, ie, make sure you select the correct external drive as "Disk 0" is likely to be the internal one)

6. Type clean (to completely erase everything including the partition structure on it, obviously assuming you've backed it up first)

7. Type convert gpt

8. Type Exit twice (once to quit DiskPart and a second time to exit the Command Prompt).

9. Reboot (just to be sure). Now go into Disk Management and create / format the drive as NTFS.

I have managed to convert to GPT without any issues now. I had to format it a few days ago and I could not figure out how to convert it to GPT. It was pretty simple, really. But I could not, for the live of me, find the option to do it. And it was pretty simple. I just didn´t notice that I could click over that left square to get a menu to tinker with the whole hard disk. Pretty silly.


Thank you guys.

Just for future reference, this sounds like one of those times where using a Linux System Rescue (USB) would have involved less banging of the head.

Found here.
Classics of stuff to keep handy, well documented. Old enough that you would burn it to a CD!

D had beat me to it with System Rescue, but another option for just Disk management:
https://gparted.org/

If you have a 32gb usb, you could dump any iso tools and entire operating systems into a tool that is called Ventoy:
https://www.ventoy.net/en/index.html

As a side not. If for some reason you did not want to copy/paste your files manually. You could clone an entire drive. Then maniuplate it with confidence, that you had a backup, before making changes. A clone tool such this, is free:
https://clonezilla.org/

or the same with graphics

https://rescuezilla.com/

Good luck :)

Does it really say "disco" in Spanish?!? Nice!

https://www.youtube.com/watch?v=zelo36ghOTQ

In portuguese and italian as well (I believe). :p

By the way. You told me that I should use Linux. Tell me which one is the most user friendly and compatible with games and internet surfing. I might give it a go. :)

I am in the process to make a dual boot in my laptop because of unable to update it to win11 and i am between Linux Mint or Bazzite.