Microsoft has indicated that the latest Windows 11 security patch is not to blame for the reported SSD failures (via BleepingComputer), although the precise cause is still unknown.

After the rollout of the Windows update (KB5063878) on August 12, users started to report problems with their SSDs and HDDs. The issue was first detected by Japanese users who faced failed and corrupted drives when managing large or multiple files on SSDs that were over 60 percent full and had the update applied. The SSD brands impacted included Corsair, Phison, Fikwot, Maxio, among others.

Microsoft undertook an inquiry and found no capacity to replicate the problem, establishing no link between the Windows 11 update and the rendered unusable drives. “After extensive investigation, Microsoft has discovered no correlation between the August 2025 Windows security update and the types of hard drive failures reported on social media,” Microsoft remarked in an update to the service alert noted by Bleeping Computer.

Microsoft worked with chip manufacturer Phison to investigate the failures in SSDs utilizing their components. Phison also communicated that they could not reproduce any issues but mentioned it “continues to closely monitor the situation in collaboration with our industry partners,” in a statement to Neowin.

Until the underlying cause is determined, Phison advised users to use a heatsink or thermal pad to prevent overheating during prolonged, power-demanding sessions. Moreover, a Phison representative told BleepingComputer that users with more than 60 percent storage utilized should “refrain from downloading, copying, or writing large files” that are in the tens of gigabytes.