Once moved to your offline machine, run Setup.bat . Note: This will attempt to download dependencies, so it is best to run this once while online, then move the entire folder.
You lack Visual Studio redistributables. Install VC_redist.x64.exe (offline version) from a USB stick. This is a common oversight.
UE4 requires specific software like DirectX runtimes and Visual C++ redistributables. Ensure these are installed on the offline PC first.