Is the Windows 11 24H2 KB5063878 Update Causing SSD to Fail?

How Can I Keep My Valuable SSD Safe from the Windows 11 KB5063878 Update?

A recent update for Windows 11 is causing some concern for computer users. If you have updated your system recently, you may have questions. This guide will walk you through what is happening. We will cover the problem in simple terms. You will learn what the issue is, who might be affected, and what you can do to protect your computer and your important files.

Microsoft released an update on August 12, 2025. This update is named KB5063878. It was intended for computers running Windows 11, specifically version 24H2. Like most updates, it was designed to improve your computer’s performance and security. However, soon after its release, some people started reporting serious problems with their storage drives. Microsoft is now aware of these reports. The company is actively looking into the matter with its partners to understand and fix the problem.

Understanding the Core Problem

The issue seems to happen to solid-state drives, also known as SSDs. These are the fast storage drives found in most modern computers. Users who have installed the KB5063878 update have, in some cases, experienced their SSDs stop working correctly. This is not a small glitch. It can lead to your computer being unable to see the drive at all. In some situations, it can cause the loss of your personal files, photos, and documents.

Here is what people are seeing when this problem occurs:

The SSD Vanishes

The most common report is that the storage drive suddenly disappears from Windows. It will not show up in File Explorer. Sometimes, even the computer’s basic startup system, the BIOS, cannot detect the drive. It is as if the drive was physically removed from the computer.

Drive Shows as ‘RAW’

In other cases, the drive is still visible to the computer, but it appears as a “RAW” partition. Think of your drive’s file system as a library’s card catalog. It tells the computer where every piece of data is located. When a drive becomes RAW, it is like the card catalog has been erased. The computer sees the library (the drive) but has no map to find any of the books (your files). This makes all the data on the drive inaccessible.

Errors During File Transfers

The problem often appears when the computer is writing a large amount of data to the SSD. This could happen when you are installing a large video game, updating software, or transferring a big folder of photos or videos. During this process, you might see error messages about I/O (Input/Output) failures, or your File Explorer might freeze or crash.

This is a serious issue because your SSD holds everything. It stores your operating system, your programs, and all of your personal data. When it fails, it can bring your entire workflow to a halt and put your valuable information at risk.

Who Is at Risk? A Closer Look at the Conditions

You may be wondering if your computer is at risk. It is important to know that this problem appears to be very specific. It does not affect everyone who installed the update. The issue only seems to occur when a particular set of conditions are met. This is why the reports are not more widespread. Most people’s daily computer use will not trigger the bug.

Based on reports and testing from users and technical experts, the problem is most likely to happen under these circumstances:

High SSD Capacity Usage

The issue seems to be more common when the SSD is already quite full. Reports suggest the drive needs to be more than 60% full for the problem to surface. When a drive is nearly full, it has to work harder to manage its storage space.

Large, Continuous Data Writes

The bug is triggered by heavy and continuous write activity. This means writing a lot of data to the drive all at once. A common example is downloading and installing a game update that is 50 gigabytes (GB) or larger. Transferring a single, very large file or a folder with thousands of smaller files can also create this workload.

Specific Drive Controllers

Early reports suggested that the problem was limited to SSDs that use a specific type of management chip, known as a Phison controller. Phison is a company that makes these controller chips for many different SSD brands. However, as more information has come to light, there are now reports of similar issues with drives that use controllers from other manufacturers, such as InnoGrit and Maxio.

This tells us that the problem is not tied to one specific brand of SSD. You cannot say that “Brand X” is safe and “Brand Y” is bad. The issue seems to be a complex interaction between the Windows update, the drive’s firmware (its internal software), and how the drive behaves when it is nearly full and under a heavy load.

Why Are Most Reports from Japan?

One curious detail is that many of the initial reports came from users in Japan. This led some to wonder if it was a regional or language-specific issue. This is unlikely. A storage drive’s controller works the same way regardless of the user’s location or language settings.

A more probable explanation is that the specific workload needed to trigger the bug is more common among a certain group of users. Japan has a large and active community of PC gamers. Games like Cyberpunk 2077 and Honkai: Star Rail, which have very large installation sizes and frequent, massive updates, are popular there. The act of downloading a 100 GB game patch onto an SSD that is already more than half full creates the perfect stress test to expose this hidden bug. As awareness grows, more reports are emerging from users in other parts of the world who have encountered the problem under similar conditions.

What Might Be Happening Behind the Scenes?

To understand the problem, it helps to know a little about how your computer and SSD work together. While Microsoft has not confirmed the exact cause, technical experts have a strong theory about what is going on. Here is a simple breakdown of the likely chain of events:

A Change in the Windows Update

The KB5063878 update likely changed how Windows 11 manages data before it gets written to the drive. The operating system uses a temporary holding area, or a buffer, to gather data. This update may have created a flaw in how this buffer is managed during long write operations.

The Buffer Overflows

When you start a large file transfer, Windows begins filling this buffer. The theory is that the system now holds too much data in this buffer without sending it to the drive quickly enough. The internal queues that manage the flow of data get too long.

The SSD Is Already Busy

This situation becomes worse if your SSD is over 60% full. A fuller drive has less free space to work with. Its internal management system, called the FTL (Flash Translation Layer), has to perform more background tasks, like “garbage collection,” to clean up and consolidate space. This makes the drive busier and slower to respond.

The System Reaches a Breaking Point

Windows keeps sending write requests, but the busy SSD controller cannot keep up. The communication between the operating system and the drive controller breaks down. At this point, the controller might simply reset itself or stop responding entirely to protect itself from corruption.

The Drive Disappears

When the controller stops responding, the SSD effectively disconnects from the system. This is why it vanishes from Windows and even the BIOS. The computer no longer sees it as a connected device.

In a less severe case, a simple reboot of your computer might be enough for the controller to restart properly, and the drive may reappear. However, in the worst-case scenario, the communication breakdown happens at a critical moment. This can corrupt the drive’s partition table—the map to your data. When this map is damaged, the drive shows up as RAW, and your files become inaccessible without specialized recovery tools.

What Is Being Done About the Issue?

Both Microsoft and the drive controller manufacturers are taking these reports seriously. This is not an issue that is being ignored.

Microsoft’s Investigation

Microsoft has officially confirmed that they are “aware of these reports and are investigating them.” They are working with their partners, including storage device companies, to pinpoint the exact cause of the problem. They have also asked affected users to submit detailed reports through the Feedback Hub application in Windows. This information is crucial for their engineers to replicate the bug and develop a fix.

Phison’s Response

Phison, the controller manufacturer initially linked to the problem, also released a statement. They acknowledged the issue and confirmed they are working closely with Microsoft to resolve it. Phison provides the core technology, but any fixes to a drive’s internal software (firmware) must come from the SSD manufacturer that sold you the drive (e.g., Crucial, Kingston, Sabrent, etc.). Phison will develop the fix and provide it to these companies, who will then release it to their customers.

Progress is being made, but finding the root cause of such a complex problem takes time. A proper solution will require careful testing to ensure it fixes the issue without creating new ones.

What Should You Do Right Now? An Actionable Guide

Hearing about potential data loss can be unnerving. However, it is important not to panic. This issue is isolated and requires a specific set of circumstances. For the vast majority of users, this update will cause no problems. Here is some practical advice on what you should do.

First and Foremost: Back Up Your Data

This is the single most important piece of advice, not just for this issue, but for all computer use. Hardware can fail, and software can have bugs. Having a current backup of your important files is your best protection against any problem. If you do not have a backup system in place, now is the perfect time to set one up.

• Cloud Storage: Services like OneDrive (which is built into Windows), Google Drive, or Dropbox are excellent for documents, photos, and other important files. They automatically sync your data, keeping a copy safe online.
• External Hard Drive: Purchase an external SSD or hard disk drive (HDD). You can manually copy your important folders to it regularly. Better yet, use the built-in Windows Backup tool or third-party software to create a complete system image. A system image is a full copy of your entire drive, including Windows, your programs, and all your data.
• The 3-2-1 Backup Rule: The gold standard for data safety is the 3-2-1 rule. Keep 3 copies of your data on 2 different types of media (e.g., your computer’s SSD and an external drive), with 1 copy stored off-site (e.g., in the cloud or an external drive you keep at a different physical location).

Check If You Have the Update Installed

You can easily see if your computer has the KB5063878 update.

1. Click the Start Menu and go to Settings.
2. Select Windows Update from the left-hand menu.
3. Click on Update history.
4. Look under the “Quality Updates” section. If you see KB5063878 in the list, it is installed on your system.

You can also check your full OS build number by going to Settings > System > About. If the “OS build” number is 26100.4946 or higher, you have the update.

Consider Pausing Future Updates

If you have not yet installed the update and are concerned, you can temporarily pause Windows updates. This will give Microsoft more time to investigate and release a fix.

1. Go to Settings > Windows Update.
2. Look for the Pause updates option.
3. You can choose to pause updates for one week or more.

This is a safe, temporary measure. It prevents new updates from being automatically installed until you are ready.

Should You Uninstall KB5063878?

This is a more difficult question. The update contains important security patches that protect your computer from other threats. Uninstalling it could leave your system vulnerable.

If your workflow involves frequent, large file writes to a nearly full SSD

If your daily work involves video editing, managing massive photo libraries, or you are an avid PC gamer who regularly downloads large patches, you may be in the higher-risk group. In this case, uninstalling the update might be a reasonable precaution until a fix is available.

If you are a typical user

If you mainly use your computer for web browsing, email, and office documents, your chances of encountering this bug are extremely low. For most people, the security benefits of keeping the update likely outweigh the very small risk of this specific SSD issue.

If you decide to uninstall it, you can do so from the Update history screen in Windows Update. Click Uninstall updates and select KB5063878 from the list. However, be aware that uninstalling the update may not repair any damage if the bug has already been triggered.

What If Your Drive Is Already Affected?

If you believe your SSD has already failed due to this issue, there are a few things to consider.

Reboot

First, try a simple reboot. In some cases, this is enough to make the drive reappear.

Professional Help

If the drive shows as RAW or is not detected after a reboot, your data is at risk. Further attempts to fix it yourself could make things worse. If the data on the drive is critical, it is best to stop using the computer and consult a professional data recovery service. They have specialized tools and techniques that may be able to retrieve your files.

Advanced Tools (Use with Extreme Caution)

Some advanced users have reported success using tools like TestDisk to rewrite the partition table or using Linux-based tools to perform a full erase of the drive. This will erase all data on the drive. This is a last resort for recovering the use of the drive itself, not for saving the files on it. This path should only be taken by expert users who understand the risks and have already accepted that their data is lost.

This situation is a reminder that the technology we rely on is complex. Bugs can and do happen. While Microsoft and its partners work on a permanent solution, the best strategy for you is to be informed, be cautious, and above all, ensure your precious data is safely backed up.