MBR to GPT.

[IronMaiden]

Ok, bear with me:

I have an HP p6754y desktop model.  Purchased in March of '11.  It's been great.  I have purchased, in the last week, a 4TB HDD.  I had one drive crash on me, and decided to do a fresh install of Win8.1.  I converted the drive to GPT using the command prompt protocol. It showed that it worked.  As soon as I exited the command prompt, Windows said it could not install the OS on a GPT drive.  I continued to do it through MBR settings and everything installed nicely, baring the reading of the unallocated space left on the drive, appox. 1.6 GB.  C drive shows that it is 1.99 GB and the OS works just fine.  I have purchased and tried to use AOMEI partition assistant PRO.  It allows me to change the drive to GPT, but I have to change the whole thing.  It included warnings about the motherboard settings need to be changed to UEFI in the BIOS.  I tried to do that through start menu/windows key +C/pc setting/update and recovery.  But, the UEFI/restart link/button is not there.  There are only five things listed when there should be six.  I don't know what FN button I need to hit to get into the Motherboard bios on startup, and can't find a solution online.  That being said, is the motherboard that came with this model even capable of being changed to accept GPT settings for a larger HDD or am I just barking up a tree that doesn't even exit?

[Paul_Tikkanen]

Hi:

You need a PC with a UEFI BIOS, which the  HP p6754y doesn't have, in order to use any drive in excess of 2 TB as a boot drive.

You may be able to use it as a secondary storage drive formatted in GPT, and see if all 4 GB are recognized but don't get your hopes up.

[IronMaiden]

That's what I thought all along, but was getting my hopes up, regardless.

Thanks.

Footnote:  I have added a 3TB hard drive with this computer about 4 years ago and it partiioned down to 1.8 and .9 TB respectively.  Both drives were usable and readable.  My OS was on the 1.8 side.  Was that maybe because I had that drive as a support drive first, then added the OS later on when my original HDD was failing?

[Paul_Tikkanen]

You're very welcome.

You can format the 4 TB drive in MBR and partition it the same way as you did the 3 TB and it should work as a boot drive.

[IronMaiden]

Tried that several times yesterday to no avail.  I must have loaded and reloaded Win 8.1 about a dozen times using different settings to get the unall. space to be usable.  It just won't read the unallocated space at all.  It shows up in the disk manager in Windows and on AOMEI partition assistant, just not in Win Explorer.

[IronMaiden]

Ok.  So I wiped a 1TB HDD, reloaded Win8.1 on that drive.  I then converted the 4TB HDD to GPT, after removing the partition.  Worked like a charm.  It is only a support drive, but it is reading the entire drive now.