How do i Revert dll file to default?

To revert a DLL file to its default version, you can use the System File Checker tool in Windows. Open Command Prompt as an administrator and run the command sfc /scannow. This will scan for and restore corrupted or missing system files, including DLLs, to their default versions. If the DLL is a third-party file, you may need to reinstall the application that installed it to restore it to its original state.