Windows 11 Insider Preview Build 26300.7939 introduces a new registry switch that prevents batch files from being modified during execution, which helps avoid "file in use" errors. Users can enable this feature by creating a DWORD value named LockBatchFilesWhenInUse in the registry and setting it to 1, which ensures that the command processor locks the batch file for the duration of its run. This change addresses issues experienced by some insiders where driver updates inadvertently altered maintenance scripts while they were executing. Although this tweak is beneficial for environments with multiple processes, it may not be necessary for single-user workstations that do not run third-party installers

Windows 11 Insider Preview Build 26300.7939 Dev Channel: What's new

Windows 11 Insider Preview Build 26300.7939 adds a registry switch that locks batch files while they execute, preventing mid‑run modifications that can cause “file in use” errors. The setting is enabled by creating a DWORD value named LockBatchFilesWhenInUse under HKLM\Software\Microsoft\Command Processor and setting it to 1. Once active, the command processor holds an exclusive lock on each batch file for the entire run, which stops rogue installers or driver updates from corrupting scripts on the fly. After applying the tweak, a simple self‑modifying script runs without error, confirming the protection is working.

Windows 11 Insider Preview Build 26300.7939 Dev Channel: What's new @ NT Compatible