Question External HDD disappeared after Windows 11 24H2 Update ?

[Damien_XIII]

Hi everyone,

I’m reaching out for help with a problem I'm facing with my laptop storage after updating to Windows 11 24H2. Here’s the situation:

Storage Devices:

• 512 GB M.2 SSD (C drive for the operating system).
• 3 TB External HDD (used for storing important files, about 746 GB of free space before the issue).

The Problem: After the update two days ago, everything worked fine at first. However, after restarting my laptop, the external HDD no longer shows up in File Explorer. When I checked Disk Management, I noticed that the HDD appears as 746 GB of unallocated space, which matches the amount of free space it had before. I didn’t create a new partition or format the drive as I’m concerned about losing my data (it’s a lifetime collection).

What I’ve Checked So Far:

• Hardware: The data cable and power supply for the HDD are confirmed to be working properly.
• Disk Management: The HDD is recognized, but shows unallocated space rather than being listed normally.

System Information:

• Windows 11 24H2
• Laptop Model: ASUS TUF F15 Gaming Laptop
• The issue started after the 24H2 update.

What I Need Help With:

• I want to recover access to my external HDD without losing any data.
• Any steps or methods that can help me retrieve the drive while preserving the data would be much appreciated.

Troubleshooting Attempts:

• I’ve checked hardware connections.
• I’ve looked at Disk Management, but I haven’t tried creating a partition or formatting it because I’m worried about data loss.
• No other software or Windows update-related changes were made that would have affected the drive.

If any of you have suggestions on how I can fix this or if you need any other system details, please let me know!

Thanks for your help!

 

[KingLoki]

Definately don't mess with partitioning and formatting. You could loose existing data.

Have you tried accessing the external on another pc?

If you can access the data you really need to backup your data if its that important onto another drive for safety.

 

[SkyNetRising]

Disk Management: The HDD is recognized, but shows unallocated space rather than being listed normally.

Please show screenshot from Disk Management.
(upload to imgur.com and post link)

 

[Damien_XIII]

Please show screenshot from Disk Management.
(upload to imgur.com and post link)

Sure. Here it is.

https://imgur.com/a/eAIFk5b

View: https://imgur.com/a/eAIFk5b

 

[Damien_XIII]

Definately don't mess with partitioning and formatting. You could loose existing data.

Have you tried accessing the external on another pc?

If you can access the data you really need to backup your data if its that important onto another drive for safety.

Thank you for the suggestion! I haven’t tried accessing the HDD on another PC yet, but I will take it to a friend’s place tomorrow to test it there. I’ll update the thread once I’ve checked it out. Thanks again for the advice on backing up the data—I’ll make sure to do that if I can access the drive.

 

[SkyNetRising]

Sure. Here it is.

Can you show full screenshot from Disk Management?
Are there any more drives being shown, if you scroll down lower portion of Disk Management window?

Can you show a screenshot from Device Manager - disk drives and storage controllers sections expanded?

 

[Damien_XIII]

Thank you for your follow-up! I’ve uploaded both screenshots you requested:

Disk Management (Full View) and Device Manager with Disk Drives & Storage Controllers Expanded
Here is the link:

https://imgur.com/a/G3t7uSU

View: https://imgur.com/a/G3t7uSU


Let me know if you need more details or screenshots. I really appreciate your help with this!

 

[SkyNetRising]

Can you show screenshot from Windows Storage Spaces (Control Panel/Storage Spaces) ?

Then go into BIOS and disable Intel RST.
Make sure SATA controller is set to AHCI mode.

 

[fzabkar]

Your USB enclosure has a 32-bit LBA limitation. You need a more recent enclosure.

3 TB - 2 TiB = 746 GiB​

https://www.google.com/search?q=3+TB+-+2+TiB++in+GiB

 

[Damien_XIII]

Can you show screenshot from Windows Storage Spaces (Control Panel/Storage Spaces) ?

Then go into BIOS and disable Intel RST.
Make sure SATA controller is set to AHCI mode.

I appreciate your input! I didn’t need to check Windows Storage Spaces or modify my BIOS settings. The issue was actually due to my USB enclosure, which had a 32-bit LBA limitation and couldn’t support my full 3TB HDD.

Once I connected the HDD directly via a SATA to USB adapter with a 12V power supply, the full capacity was immediately restored without any need to change BIOS settings. But I’ll still keep your suggestions in mind for future troubleshooting. Thanks again for your help!

 

[Damien_XIII]

Your USB enclosure has a 32-bit LBA limitation. You need a more recent enclosure.

3 TB - 2 TiB = 746 GiB​

https://www.google.com/search?q=3+TB+-+2+TiB++in+GiB

You were absolutely right! The issue was caused by my USB enclosure’s 32-bit LBA limitation, which capped the accessible storage at 746GB instead of the full 3TB. After reading your response, I swapped out the enclosure and connected the drive using a SATA to a USB adapter with a 12V power supply, and it instantly showed the correct storage size.

A huge thanks to you. Your detailed explanation about the LBA limitation and calculation really helped pinpoint the issue. Your knowledge saved me a ton of time—much appreciated! 🚀