It’s the RTM build number embedded in the MSDN filename. Later MSDN ISOs for Windows 8 had different numbers, but “916083” refers to the first public release.

: An ISO file (or ISO image) is an archive file that contains an exact copy of data found on an optical disc, like a CD or DVD. Users can mount ISO files as virtual drives or burn them to physical media.

The "best" way to handle the missing Start Menu is to install (formerly Classic Shell). This restores the Windows 7-style Start Menu and boots directly to the desktop.

: For genuine software and to avoid any risks associated with pirated software, it's recommended to use official channels like MSDN.