MBR vs GPT (for people who are getting the "D:\ is not accessible. The Volume does not contain a recognized file system...."

You misread the issue.

The issue occurs AFTER you install windows 8.1.

This has nothing to do with Windows 8.1 installations.

Read this carefully please. The issue is related to installing extra hard disks after Windows 8.1 has already been installed on a GPT hard disk.

My PC has 5 SATA drives, and 1 SSD drive. Windows 8.1 is installed on the SSD drive fine, with GPT. No problems there. The SSD drive was new, and had no data on it. The problem comes next.

The other drives came from a Windows Vista PC, and they had MBR partitions. After I installed those drives in my PC running Windows 8.1, Windows 8.1 told me that the drives were not formatted, even though they already WERE formatted and were full of data.

Here's the process:

1. Installed Windows 8.1 on clean SSD drive using GPT partition tables (default settings).
2. Took working SATA drives with MBR partitions from another PC and connected them to the Windows 8.1 PC by SATA III cables.
3. Windows 8.1 PC detects the SATA drives and says they are unformatted and need to be formatted before they can be used.
4. The drives are already formatted with MBR, and contain lots of data which I did not wish to lose.
5. Used testdisk to copy the data off those drives onto another drive which is running GPT.
6. Format the previous disks using GPT.
7. Copy the data back to the previous disks.
8. Previous disks work fine.

The issue is not about what kind of partition Windows 8.1 can be installed on. It's about connecting other drives to the PC that already has Windows 8.1 installed on it, which was the issue that other people were having and which I was addressing.

I don't know if the issue has been addressed by Microsoft yet, but that was the issue I had a few months ago.

I really think there is a misunderstanding here about the issue I'm talking about.

First of all, it's not a simple solution such as simply converting between MBR and GPT because that forces you to initialize the drive, losing all of your data....

I think we're talking about different things here. I'm talking about a hard drive from a older PC running Vista or Windows 7 (which has existing data on it which we do not want to delete), being transferred to a new PC running Windows 8.1. Based on the article you posted, many new PC's use UEFI (like mine) instead of BIOS. UEFI basically forces you to use GPT. I didn't know about that so I appreciate you posting that article. It had some useful information in it... however, it does not provide a solution to the problem. The fact that my motherboard uses UEFI could be why I was having problems but it didn't change the fact that I had to convert 3 hard drives to GPT. My motherboard is pretty new. An ASUS x99-Deluxe slot 2011-3 with a Haswell 5930K processor. It uses UEFI. So maybe that was significant... I don't know.

And this is taken from the article you posted:

"You can actually switch back and forth between MBR and GPT partition types by right-clicking on the drive in Disk Management. The problem is that before you do, you’ll need to delete all of the partitions on the disk, which does make the feature slightly less useful."

Deleting a partition means losing data....

Also, this is relevant:

"Have you ever inserted a drive into your PC only to be presented with a dialog asking you to Initialize Disk?

What’s actually going on is that Windows didn’t detect any partition table format, so it will ask you to “Initialize”, which really just means write out a new blank partition table. In modern versions of Windows, that means you’ll get a choice between MBR and GPT.

Note: just because Windows didn’t recognize any partition information doesn’t mean that your drive is blank. If you know that the drive works, it’s possible that you are having a driver issue, or in some cases, if you plugged in an external drive, you can remove and then plug it back in again. Of course, if you selected GPT as the partition table, it’s also possible that the PC’s BIOS can’t handle it."

The last sentence "It's also possible that the PC's BIOS can't handle it." might have been the issue for me... however, it's still an issue. It might be fixable, but it's still a problem to be dealt with. 3 inaccesible drives is an issue for me anyway.

To be clear, when I took my external drives and installed them in my new desktop, windows did not recognize their partition tables, and told me to initialize the disks. Is that a problem? Yes, because I had data on those disks I didn't wish to lose. It also warned me that if I initialized, the data would be lost. Hence, the issue of getting around that problem.

Of course, I knew that the disks had been working previously and had already been initialized on my old laptops. I didn't want to lose my data, so I had to find a way to save it.

And another key point is that one of the drives worked fine when I installed it... and low and behold, it already had GPT installed. The 3 that didn't work were all MBR. Is that a coincidence? Maybe... but the fact was, I couldn't access 3 hard drives that all had data on them already... to me, that is an issue. You keep saying this is not an issue... I guess data doesn't matter to you?

I'm not making this stuff up... I had 3 drives. They all worked fine when they were connected as USB drives to my old laptops which were running Vista and Windows 7. But I take them out of the plastic external cases, detatch the USB adapters, install them in my Windows 8.1 system as internal drives, and suddenly they can't be accessed without being initialized. Am I making this up? Did I imagine it? No... it happened, it's an issue, and other people have had it.

If you have an easy solution, please provide it. So far, you have provided only partially relevant information which I can appreciate, but you still haven't addressed the problem I had.

Yes, converting is easy, if you don't mind losing all your data.

Like I said, Windows 8.1 will force you to initialize the drive using GPT to the best of my knowledge, especially if the drive is large, like a 3TB or 4TB drive (All of my drives are 3 TB or more). It might be based on the BIOS type or settings as you say. If that's the case, then a simple change in the BIOS / UEFI settings might correct the problem as well. I never found any information about that kind of fix... However, that is still an issue people need to know about, and need a solution to. If you know how to do that, then please post the information.

I'm not here trying to make trouble for anyone ... just trying to help people who had a similar situation as me.

I get what you're saying... the issue was with my BIOS settings, not Windows 8.1. Fine, you're probably right, but the problem still exists, even if I was wrong about the source of the problem....You didn't have to say "it's not an issue"... or you should have said "Windows 8.1 is not the issue". That would have made more sense.

Cause when I transferred my drives, they didn't work. If the BIOS was the culprit, then that's good to know. But my drives not working... to me, that is still an issue. You might have an easy solution for it which I didn't. But it's still an issue that requires a solution right? Not trying to be a jerk or anything. Just want you to acknowledge that this is "an" issue of some kind... I won't argue with you about the source of the problem and the solution... you seem to know what you're talking about.

I didn't know about the legacy setting in the BIOS... as I'm sure a lot of people don't. I'm glad you told me about it. This is the first time I've heard of that setting... I'll have to take a look. I'm guessing I'm going to bang my head against a wall if it's there...

And I'm not too familiar with newer OS's and hardware to be honest. My previous laptops are both about 5 years old. I wasn't familiar with the changes in partition tables in newer operating systems or UEFI. I'm still learning about that stuff..

Anyway, there are other threads about this "issue". Whatever you want to call it. I was just trying to help out. Sorry if my information is bad.

And if there are utilities for converting MBR to GPT, that's great. I wish I had known sooner. I searched google many times trying to find software that could do that. I typed in "MBR to GPT conversion" as my search... I got nothing but crap... that program you listed Hawkeye22 never came up for me unfortunately.

Many programs claimed they could do it, but you have to pay money for licenses... and honestly, they didn't look trustworthy. Besides, I also think that's crazy that I have to get a 3rd party program to do something that Windows should do in the first place.

And why doesn't Windows 8.1 recognize the problem with the BIOS not being set to support Legacy partition tables? It just gives a vague error message, that is not even related to the problem. If Windows could have at least pointed me in the right direction, rather than just telling me my drive had no file system.... jeez...

I'd like to add that most people had no idea what was wrong with this situation like me....in other threads I mean... many people were blaming the NTFS file system, and all kinds of crap, drivers, etc.... check the forums if you don't believe me.

Anyway... Guess that's that... Appreciate your time in this thread though. Sorry if I caused any trouble.

Did a little further reading. The first article you posted has all the correct information regarding the issue:

http://technet.microsoft.com/en-us/library/dn336946.aspx (Just reposting it again)

I should have booted my PC in Legacy BIOS mode, and then I could have accessed those 3 MBR drives I think...

However, of course I want to use GPT for all of my drives, and I want to use UEFI, so therefore, I would have had to format my 3 drives anyway, or as Hawkeye said, use a 3rd party utility to convert them.

I guess that's the simple way of looking at the issue.

Interesting... wish I had known before... seems simple enough.

Thanks. Sorry about my reactions. To be honest, I was in bit of a mood... I had just finished dealing with Steam Support trying to get a refund for a game which they denied quite unappologetically... and then I read your reply to my forum post.

I know Steam's policy doesn't allow refunds. But I figured they might be like SONY. SONY has the same policy basically, but they gave me refunds a few times. I thought maybe Steam cares about customer satisfaction more than just grabbing people's money.

I know that's off topic, but just trying to give you a sense of where my head was at...

Anyway... trying to figure out how to give you credit for the solution, but can't seem to find any kind of button or link to do it... is there some reason I might not be able to see the button? I remember seeing it somewhere before...