Microsoft Azure CTO Mark Russinovich explained the technical reasons behind the 'File in Use' error in Windows systems in a video on the official 'Microsoft Developer' YouTube channel. He pointed out that this phenomenon can be traced back to the 1990s and primarily stems from three types of system-level locks: antivirus software retaining file handles during scans, other devices on the local network referencing the file, and implicit locking caused by DLLs being loaded via memory mapping. These locks are implemented through file handles, and the system prohibits operations by default to prevent data corruption. Users can troubleshoot using Handle or Process Explorer from Microsoft's Sysinternals toolkit, or use the File Locksmith module in PowerToys to locate and terminate the occupying process with one click.
