Microsoft Confirms Disappearing SSD Bug in Windows 11 August 2025 Update
On August 12, 2025, Microsoft released its monthly Patch Tuesday update for Windows 11 version 24H2—specifically, KB5063878 (Build 26100.4946).
⚠️ Background: A Troubling Update
On August 12, 2025, Microsoft released its monthly Patch Tuesday update for Windows 11 version 24H2—specifically, KB5063878 (Build 26100.4946).
Shortly after, users began reporting alarming storage issues: SSDs disappearing from Windows, input/output (I/O) errors, and data becoming inaccessible after large file transfers. Microsoft has since confirmed the reports and is working with hardware vendors to investigate.
🔎 Symptoms & What Happens
Affected users observed the following behavior:
- During large write operations (≥ 50 GB) on drives more than 60% full, SSDs vanish from File Explorer, Device Manager, and sometimes even BIOS.
- Some drives reappear after a reboot, but others show partitions as RAW, making data recovery difficult or impossible.
- Early testing shows the issue is more frequent on Phison-based and DRAM-less SSDs, though it is not exclusive to them.
In extreme cases, users lost access to critical data.
🗨️ Microsoft’s Response
- Microsoft acknowledged the reports and is collecting feedback through the Feedback Hub.
- Phison, a major SSD controller maker, is also investigating.
- Meanwhile, another patch (KB5063875) broke recovery tools like “Reset this PC”, prompting Microsoft to issue an out-of-band (OOB) fix KB5066189.
Clearly, this August update batch has been one of the more problematic ones in recent memory.
✅ What You Should Do Right Now
1. Avoid Large File Transfers
Break large jobs (like game installs or backups) into smaller chunks until a fix arrives.
2. Delay the KB5063878 Update
If you haven’t updated yet, consider pausing Windows Update to avoid SSD risks.
3. Backup Your Data Immediately
Follow the 3-2-1 rule:
- 3 copies of your files
- 2 different storage types (SSD + external HDD/cloud)
- 1 copy offsite
4. Apply KB5066189 if Needed
If your recovery/reset options are broken after KB5063875, install Microsoft’s emergency fix.
5. Report the Issue
Submit reports via Feedback Hub—the more data Microsoft receives, the faster a permanent fix will come.
📊 Quick Summary
| Issue | Cause (August 2025) | What To Do |
|---|---|---|
| SSDs disappearing / I/O errors | KB5063878 + heavy writes | Avoid large transfers, backup data |
| Recovery tools broken | KB5063875 | Install OOB patch KB5066189 |
| Fix status | Microsoft + partners investigating | Wait for official patch, report issues |
🔮 Wrapping Up
While not everyone is affected, the risk of SSD corruption and data loss makes this bug serious. Until Microsoft provides a confirmed fix, the best approach is caution and backups.
Stay safe—and don’t let your SSD vanish into thin air.
