WinRAR allows archive creators to lock an .rar archive or SFX executable (.exe) in order to protect the RAR packed or packaged archive from modification and change. When the WinRAR archive is locked, everybody cannot change the content in the archive, be it files, folders, comments, SFX options and modules.
WinRAR Unlock unlocks locked WinRAR archive (including SFX) allowing you to modify the content freely. Through some patching of few bytes, you are able to modify your archive with ease.
WinRAR Unlock is a freeware with no payment required.