Windows 7, 64 bit OS

Disk 0: 300GB for OS
Disk 1: 2TB for storage
Disk 2: 4TB for media storage
Disk 3: 4TB for backup of media

Disk 3 is new. I recently reimaged my computer back to my factory settings image. I formatted Disk 2 and installed Disk 3. I planned to have it running with RAID 1 but discovered much to my dismay that Windows 7 doesn't support RAID 1 and nor does my bios. I resigned to having a simple backup system instead for the time being and reinstalled all the software I wanted to keep.

Prior to the reimage, Disk 2 was seen and used by windows as a 4TB hard drive.

When I reformatted the disk I mistakenly selected MBR and started copying my data back across. I hit the limit and realised that I had initialised both disks into MBR. After looking through the web I found how to clean the disks through Diskpart on CMD and then reinitialise them into GPT. However, this has not fixed the problem at all. I still have a massively frustrating limit on size of 1677.90GB for both drives. See picture.

enter image description here

I am really finding this frustrating. All the advice online says to convert the disk to GPT and it will fix the issue. They are both now of GPT. Prior to the reimage Disk 2 was seen by the computer as having 4TB (well more like 3.6TB) so I cannot believe that suddenly the BIOS is creating an issue. I don't know what to do.

How do I make Windows see the disks for their true size? Thank you.

  • You may have to use a third party software to convert the disk to GPT and create the 4tB volume you desire
    – Kinnectus
    Commented Aug 6, 2019 at 9:55

1 Answer 1


You may convert a disk from MBR to GPT by using Disk Management. Note that this will destroy any data on the disk (for conserving data you need a third-party product), and note also that on Windows 7 this will work in your case only because you are still booting from an MBR disk (GPT only used for data).

  • Start Disk Management

  • If the disk contains any partitions or volumes, right-click each and then click Delete Partition or Delete Volume, until the disk is all one unallocated space.

  • Right-click the MBR disk and then click Convert to GPT Disk.

  • Format the disk as one volume of type NTFS

If the disk has been correctly formatted as GPT and NTFS, but it still does not show the correct size, it is possible that you need to update the Intel Rapid Storage Technology (Intel RST) driver, in order for the chipset driver to recognize GPT large disks correctly, as follows:

  • Create a System Restore point first as backup
  • Surf to the Downloads for Intel Rapid Storage Technology (Intel RST)
  • Set "Filter by" to "Drivers"
  • Choose the right OS version
  • Among the displayed downloads, choose the one that best fits your Windows version
  • Install the downloaded driver
  • Reboot
  • The author already converted the disks to GPT.
    – Ramhound
    Commented Aug 6, 2019 at 10:54
  • @Ramhound: Doesn't look like it.
    – harrymc
    Commented Aug 6, 2019 at 12:15
  • @harrymc As explained in the question, I have already done this and it has proven unsuccessful.
    – joe92
    Commented Aug 6, 2019 at 14:16
  • Have you used the Disk Management method or the diskpart method to convert to gpt?
    – harrymc
    Commented Aug 6, 2019 at 15:17
  • @harrymc Disk Management. I don't know how to use Diskpart to convert the disks, only how to use the clean method to set them as needing to be reinitialised.
    – joe92
    Commented Aug 6, 2019 at 18:16

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .