Windows 10 Anniversary Update Might Hide Partitions After Install

Steve C · 16 Aug 2016

Perhaps someone should charge MS with a class action law suit for all the customer's time wasted in sorting out poor software QA like this from MS. Then they may improve!

CaelThunderwing · 16 Aug 2016

Slartybart said:

Glad to hear your drive was not affected - I think only a small number of people have been affected.

Please clear up one thing for me: GPT Protected Partition is only when the drive is connected to the XP box ...
it is normal when connected to the Win10 1607 box - is that correct?

Curious that the drive was inaccessable for an hour

HAL was working on it
Attachment 96406

yea works fine in any of the Windows 10 systems in teh house but teh XP system (GPT Protected), the Win2k Laptop (shows RAW) and my Mac G5 tower (Read Only) (forgot to mention that mac is indeed running OSX 10.5.8)

BunnyJ · 16 Aug 2016

Steve C said:

Perhaps someone should charge MS with a class action law suit for all the customer's time wasted in sorting out poor software QA like this from MS. Then they may improve!

that's a good one.. ..

Slartybart · 16 Aug 2016

CaelThunderwing said:

yea works fine in any of the Windows 10 systems in teh house but teh XP system (GPT Protected), the Win2k Laptop (shows RAW) and my Mac G5 tower (Read Only) (forgot to mention that mac is indeed running OSX 10.5.8)

That all seems normal - thanks

XP x86 will show GPT disks as GPT Protected Partition

Win2k doesn't know about GPT

Answers about Windows disk support

Can Windows XP x64 read, write, and boot from GPT disks?

Windows XP x64 Edition can use GPT disks for data only.

Can the 32-bit version of Windows XP read, write, and boot from GPT disks?

No. The 32-bit version will see only the Protective MBR. The EE partition will not be mounted or otherwise exposed to application software.

Can the 32- and 64-bit versions of Windows Server 2003 read, write, and boot from GPT disks?

Starting with Windows Server 2003 Service Pack 1, all versions of Windows Server can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on Itanium-based systems.

Can Windows 7, Windows Vista, and Windows Server 2008 read, write, and boot from GPT disks?

Yes, all versions can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on UEFI-based systems.

Can Windows 2000, Windows NT 4, or Windows 95/98 read, write, and boot from GPT?

No. Again, legacy software will see only the Protective MBR.

Is it possible to move a GPT disk to another computer?

You can move, or migrate, data-only GPT disks to other systems that are running Windows XP (64-bit edition only) or later versions of the operating system (32- or 64-bit editions). You can migrate data-only GPT disks after the system has been shutdown or after the safe removal of the disk.

Mac - not sure. I've read that if the drive was not removed safely (Windows) , then it might show up as read-only on OSx10.

rwhite1 · 19 Aug 2016

Venting may be fun, but what we need now is a solution.

I contacted a major drive manufacturer today about this problem. This is the summary of his comments:
They are getting a number of calls about this problem. The problem is most likely to occur for external USB drives attached during the upgrade. It happens with USB drives more often than internal drives. The problem occurs for both USB 2 and 3. My case was the first he had heard of on an SATA drive. All the calls he has gotten up 'til now have been IDE. His recommendation is 1) do the update with any external drives disconnected. 2) If the problem occurs DON'T WRITE TO THE DRIVE. The data is still here. Put the drive on a 1511 system, copy the data from the drive, put the drive back on the 1607 machine, use Disk Management to initialize and reformat it, then copy the data back from the 1511 machine. It worked for me, although cumbersome and an unnecessary waste of time. His other comment was interesting, but not of much help here: This happens more often on MAC upgrades than PC's. I might also note that I also tried recovering the partition with MiniTool Partition Manager, but that only made the drive unreadable in both 1607 and 1511.

Reformatting seems to be the only successful method so far. I hope I'm wrong about that and someone has found a better way.

Steve C · 26 Aug 2016

Does anyone know when MS intends to fix this serious problem? I'm delaying upgrading my desktop PC which has 4 drives (3 internal & 1 external) until this problem is solved.

BunnyJ · 26 Aug 2016

Steve C said:

Does anyone know when MS intends to fix this serious problem? I'm delaying upgrading my desktop PC which has 4 drives (3 internal & 1 external) until this problem is solved.

I had this occur to me and all I had to do was to bring up the disk manager and assign a letter to the drive.

Fast and simple fix..

alphanumeric · 26 Aug 2016

BunnyJ said:

I had this occur to me and all I had to do was to bring up the disk manager and assign a letter to the drive.

Fast and simple fix..

My drive showed up as RAW, there was no simple fix for me. I ended up re partitioning and formatting it. Then copying all my files back from my backup.

BunnyJ · 26 Aug 2016

alphanumeric said:

My drive showed up as RAW, there was no simple fix for me. I ended up re partitioning and formatting it. Then copying all my files back from my backup.

That stinks.. but in my case I just had to assign a letter/value to the drive and it was fixed.

alphanumeric · 26 Aug 2016

BunnyJ said:

That stinks.. but in my case I just had to assign a letter/value to the drive and it was fixed.

I "think" they are two separate/different glitches. Might also depend on whether its an external drive or internal drive. Mine was an internal SATA drive. Motherboard chip-set might factor into it too. Lots of variables.