Cannot partition unallocated space on 4TB hard drive

tahaminey said:

How do I get to command prompt without booting from hard drive. I'm not sure how to get it to boot from disc.

You get to a command prompt exactly as I told you: Boot from the install disc and hit Shift F10 at the language screen.

You boot from the install disc by putting the Windows install disc in your DVD drive and restarting the PC.

As the reboot procedure begins, you will need to get to a "boot menu" where you choose the DVD drive as the boot drive, NOT the hard drive.

You get to the boot menu by hitting a key on your keyboard as the reboot begins. Hold that key down.

What key? It varies. So experiment.

It's probably an F key or maybe delete. I'd try F8 first. If that fails, try F2. If that fails, try delete. If that fails, try other F keys. Just hold it down. If you don't see a menu pop up, you chose the wrong key.

When you see the menu, use your arrow keys to select the DVD drive and then hit the enter key.

Okay. I will give it a try and see how I how. This is nerve racking. I'm so worried I'm going to stuff it up.

tahaminey said:

Okay. I will give it a try and see how I how. This is nerve racking. I'm so worried I'm going to stuff it up.

I just tested on my own PC. It uses F12 to access the menu.

The boot menu can be cranky to bring up. Sometimes you have to tap the key once a second. Or maybe twice a second. Or maybe just hold it down. It varies, as I said.


Don't worry about fouling things up. You've already said there is nothing on the drive you care about. If you enter a bad command in diskpart, it will just tell you it doesn't recognize the command. In which case, re-read the tutorial or ask questions. There's not much you can do to the drive to ruin it. After all, your intent is to delete everything on it anyway.

Print out or write down the relevant portions of that tutorial if it makes you more confident.

Okay I don't know what I did wrong but it's still not working.

In the command prompt it said successfully converted to GPT so I exit and restart and then install windows but when I went to check the disc it still says 1.64 unallocated and it stills says MBR.

The Bly thing I did different was I had to select disk 0 instead of select disk 1 because it said disc 1 had no media.

Should I have installed windows after converting to GPT without restarting?

Should I try converting again?

tahaminey said:

Okay I don't know what I did wrong but it's still not working.

In the command prompt it said successfully converted to GPT so I exit and restart and then install windows but when I went to check the disc it still says 1.64 unallocated and it stills says MBR.

The Bly thing I did different was I had to select disk 0 instead of select disk 1 because it said disc 1 had no media.

Should I have installed windows after converting to GPT without restarting?

Should I try converting again?

What, exactly, do you mean by "it still says MBR"? What is "it" and where are you getting that information?

I assume you now have Windows installed on this 4 TB disk.

When you exited disk part, did you then reboot with the Windows install disk in the DVD drive and again choose the DVD drive as the boot device?

Or did you just continue with the installation without rebooting?

I wouldn't think you could have converted the disk from MBR to GPT if your motherboard didn't support it. But I'm no expert on Diskpart. I'll take your word for it that you in fact successfully converted from MBR to GPT.

It certainly can't hurt to redo it.

after exiting command prompt I restarted with the disc still I the dvd drive and then it installed windows. When I went into disk management it still showed 1.64tb as unallocated and when on click on properties in that space it said MBR. My excitement deflated after I saw that it was still unallocated.

Anyways I went to that YouTube tutorial showing how to access full capacity using seagate disc-wizard and it looks like it has worked now. I have access to the unallocated space snd have been able to partition in into 3 more partitions. If made the unallocated dosce as a second disk.

So now I'm disk management it says disk 0 which is the first 2tb and disk 1 which us the 1.64tb which was previously unallocated.

The only thing is in the disk 0 row it still shows 1.64tb as unallocated like before but you can't do anything to it. However that space is now disk 1. On the tutorial after completion theirs didn't show the unallocated space in the originsl disk 0 was gone.

Apart from that, it send to be working. I don't know if it's ok to use it as is since I can access all the space now. When I click on my computer it shows all the partitions thst I've created. Only whe I go into disk management it shows that unallocated space.

Should I leave it and start installing my programs?

I'd say you have an MBR disk and have also used auxiliary Seagate software that will allow you to see and use the entire disk in some way. It artificially created a disk 1, when in fact you have only disk 0.

What it won't do is allow you to use all 4 TB as part of a single disk.

I don't understand why your supposedly successful conversion to GPT did not stick.

Are you willing to try this:

Reboot from your install disk again, using that F key that brings up the menu.

Select the DVD drive from that menu and boot. Again delete all partitions and convert to GPT, just as you did before.

Immediately after getting the notification that the conversion to GPT was successful, make a 4 TB partition, while still in diskpart.

The following commands should work, entered one at a time:

create partition primary

Or if you have some idea of how large you want C to be, instead of "create partition primary", you would enter "create partition primary size=120000"

That would create one partition of 120 GB instead of making a 4 TB partition of the entire disk.

select partition 1 (this selects the partition you just made)

active (this marks that partition active)

format fs=ntfs quick (this formats that partition)

exit (this quits the diskpart program)

That should drop you back into the Windows installation at the language screen. Select your language and continue. When you come to the screen asking "where do you want to install Windows", choose the partition you just made in diskpart.

whs said:

Ignatz, Maybe you want to suggest the bootable CD of Partition Wizard

I'm sure that would "work" WHS.

But the problem is, the OP already claims to have successfully converted from MBR to GPT per a message saying so in Diskpart and nonetheless could not then see all 4 TB of the drive after installing Windows. So he then went on to use Seagate Disk Wizard, a workaround for MBR.

So I have just suggested he again convert to GPT in Diskpart and immediately make at least a C partition in Diskpart, rather than letting Windows create partitions later on.

What do you think?

I don't understand why his Diskpart conversion from MBR to GPT did not take. I have to assume his motherboard and BIOS support GPT or else Diskpart would not have allowed the conversion (??)

So do I do everything again in command prompt and when it says successful just do the added instructions to create primary partition as 4tb?

I will try. Give me some time. I am a bit slow.