6TB HDD, but BIOS won't allow over 2TB

Thanks lehnerus. I'll look into that. That's the funny thing about it, it worked when the PC guy did it, but after I shrunk it I couldn't extend it again, not even by a single MB. I'm reading your post now.

Can you post a full disk manger showing all the details at the top

I'm using AMD's SATA Controller that's up to date. Can I use Intel's Rapid Storage Technology Drive instead?

Mellon Head said:

....it would probably mess more than a few things up.

lol. I knew that was stupid when I asked it, but everyone's born ignorant. Thanks for not flaming me.

Escar Frazzle said:

This is before I realized that I can't run a HDD over 2TB. Coincidentally I had already upgrade to two 2TB HDD's a couple of years earlier so I never knew about the problem with my BIOS yet.

Your screenshot shows you are in fact running a HDD larger than 2TB, so I'm going to extrapolate your statement above to mean your BIOS does not support UEFI or booting from a GPT disk. Referring to the limit as "2TB" is misleading because it will depend on sector size. The 2TB limit is only true if you assume a sector size of 512 bytes.

You haven't stated, but I'll make a guess at other relevant facts: your HDD appears to be using a MBR partition layout rather than GPT, and your HDD is using a 4Kn ("4 KB Native") sector size. Please verify whether or not my assumptions are correct as follows:

In your Disk Management screenshot, right-click on the left end of the disk schematic (where it says "Disk 1") and select "Properties". Select the [Volumes] tab, and note the "Partition style". It should be either GPT or MBR. (I'm guessing MBR.)

Open a command prompt window and enter the following command: "fsutil fsinfo ntfsinfo c:"
Note the "Bytes per Sector" value. It should be either 512 or 4096. (I'm guessing 4096.)

Here are the ramifications of what you discover.

The MBR partitioning scheme allows for only four primary partitions, or three primaries with one extended partition containing one or more logical partitions. Your Disk Management screenshot shows four primary partitions already exist. So if it is indeed a MBR disk, you cannot create another partition. There's no way around that without deleting one of the other partitions.

The GPT partitioning scheme supports up to 128 primary partitions. However, if your BIOS does not support UEFI booting then you can't boot from a GPT disk. It can be used as a secondary disk, but not as your primary boot disk.

Based on your statement about the BIOS, plus the fact your screenshot does not show an EFI partition, I'm guessing it's initialized as a MBR disk.

Legacy HDDs used a sector size of 512 bytes. This is where the oft-heard "2TB" figure comes from, and is based on the maximum numbers of sectors a MBR disk can address. Your HDD, like all large disks today, will be called "Advanced Format" because it uses sectors of 4096 bytes internally. For compatibility with legacy systems, however, many large HDDs use an interface that makes each 4096-byte internal sector appear to the outside world as eight 512-byte sectors. This is called 512e ("512-byte emulated").

In 512e mode a large HDD can only use the first 2TB on a MBR disk. However, some operating systems are capable of using the HDD in "native" mode instead, seeing each sector as 4096 bytes--hence the term 4Kn ("4KB native"). The fact you appear to have a MBR disk showing up as more than 2TB suggests to me that it's 4Kn rather than 512e.

Per this reference, Windows 7 does not support 4Kn, but Windows 8 and 10 do.

Now, at this point let's note you're in a Windows 7 forum, but your System Specs indicate your OS is Windows 10. Thus, you're in the wrong place. Win7 doesn't support the disk configuration you're using, so your issue won't be familiar to most users here. The Win10 folks are more likely to be able to help you.

One final aside: you said it's a 6TB HDD, but the Disk Management screenshot is showing it to be a 5TB disk. I'm not sure what's going on there, but it's something else you may want to figure out.

All right, I'm in school today. That's why I came here. Don't know what to learn if you don't know what questions to ask.

The partition style is MBR and Bytes Per Sector are 512. Took me a second to realize I needed to run as admin. I told you I was a noob.

I was hoping to scoot by with windows 10. It looked like the responses here were quick. I knew I should have stuck with Win 7. I forgot I had a 5TB and not a 6, probably because I couldn't use all of it anyway, an oversight on my part. When you stated I can't have more than four partitions that was a problem, but only part of it. So adding a new one is out, but I'm still stuck not being able to extend D: after I shrunk it. I lost a half TB that I would like to get back.

Even though I upgraded, if you call it that, can I stay? I didn't want to lose support for 7 after a while.