This is a Windows system installed file with Windows File Protection (WFP) enabled.
There are 46 versions of remotepg.dll in the wild, the latest version being 6.3.9600.16384 (winblue_rtm.130821-1623). The average file size is about 97.85 KB.
(Note, the behaviors below are for all versions of remotepg.dll, select a unique version for details.)
Located in the registry at 'SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Approved'
United States installs about 47.76% of Remote Sessions CPL Extension.