by Ken Task.
Thanks, Matteo! Had reached beyond my 'comfort zone'! ;) So I was wrong ... not IIS but PHP.
Wondering ...
http://windows.php.net/qa/
x86_64 Builds
The x64 builds of PHP 5 for Windows are experimental, and do not provide 64-bit integer or large file support.
PHP 7 provides full 64-bit support. The x64 builds of PHP 7 support native 64-bit integers, LFS, memory_limit and much more.
QA binaries are NOT intended for production use; please use the binaries at PHP Windows downloads.
http://windows.php.net/download/
Anyone run PHP 7 on Windows verify 2gig+ file support backups? Supposedly, PHP 7 supports in Moodle have been 'back-ported' to 2.9.latest when 3.0.1 was released.
'spirit of sharing', Ken