In early February, reports of Samsung laptops, Galaxy Book4 devices in particular, affected by a weird storage issue started to pop up. Users were seeing error messages on their laptops saying "C:\ is not accessible," locking them out of their system's main drive. At first, this felt like a Windows Update problem since the timing coincidentally aligned with one, but deeper investigation revealed otherwise.
Microsoft and Samsung both came to the conclusion that the Galaxy Connect app that comes preinstalled in these devices was the culprit. The app is used to share or mirror your display to Samsung Galaxy phones, but apparently it interacted with Windows in a way that forced the OS to revoke permissions in the background. The exact details of what went wrong weren't disclosed.
But we do know that it would become impossible to access the drive once you faced the issue. You'd also be prevented from opening Office apps, system tools, web browsers, Quick Assist, and more that was stored on the C: drive. Administrative tasks or any other specific user operations might be affected, too, and users weren't able to uninstall updates or collect logs due to permission failures.
Around the same time, the February 2026 security update for Windows 11 had come out, leading some to believe it must've broken something, but that's not the case. Reports of this issue actually began emerging before the patch rolled out. Since the problem was discovered, Microsoft already logged it as a known issue on its website around ten days ago, and by March 16, it was marked as "externally resolved."
Microsoft has published a full recovery article for affected users that includes detailed steps to gain back control of your C: drive. To ensure something like this doesn't happen again, the company also pulled the Galaxy Connect app off the Microsoft Store and Samsung, and in the meantime, replaced it with an older version that's not broken. So, at the moment, only those already affected need to take action.
