Microsoft released the KB5075039 update for Windows 10 to fix a long-standing issue preventing access to the Windows Recovery Environment.
The update addresses a flaw introduced in October 2025 that broke the recovery tool for users. Microsoft stated the fix is necessary for systems affected by previous updates that disrupted WinRE functionality.
In October 2025, Microsoft confirmed that the KB5066835 Patch Tuesday updates broke USB mouse and keyboard input in the Windows 11 Recovery Environment. The company released a fix for that issue but did not disclose that a separate update for Windows 10 had also caused problems. The Windows 10 KB5068164 update, released in October, was later found to prevent the Windows Recovery Environment from starting successfully.
Microsoft disclosed the WinRE issue in the February update to the KB5068164 change log. “This update contains an issue that prevents the Windows Recovery Environment from starting successfully,” the change log stated. The company released KB5075039 on March 3, 2026, to resolve the problem.
The KB5075039 change log states, “Fixed: WinRE would not start after installing the October 14, 2025 update KB5068164.” To install the new update, the WinRE partition must be at least 256MB in size. Microsoft advises users to back up data before resizing the partition.
The Windows Recovery Environment is a minimal troubleshooting tool used to repair or restore the operating system after a failure to start, diagnose crashes, or remove malware.
