The 32-bit "install.exe" has it's permissions automatically elevated
on Windows Vista and up just based in the fact that it has the "install"
keyword in it's name, which appears to be done for backwards compatibility
by Microsoft. This is why the 32-bit install.exe doesn't have
to be run explicitly in "Run as Administrator" mode.
However, this does not work for the 64-bit "install.exe".
This can be resolved by embedding a manifest into the executable,
which instructs Windows that the executable requires elevated
permissions.

The manifest file "launcher.manifest.xml" can be embedded into the install
executable using the "Manifest Tool(mt.exe)", which comes with Visual Studio,
used as follows in the "Visual Studio Command Prompt":

"mt -manifest launcher.manifest.xml -outputresource:launcher.exe"

This requires IM to maintain two different versions of it's UI and command line
64-bit launchers("eclipsec" and "launcher" - non-admin and admin versions.
The admin version of the launchers is stored into a separate "x86_64_admin"
folder in the manually crafted "org.eclipse.equinox.executable" feature used
by the "build-im.xml" script.