That's probably because your routes and rolling stock are installed per the MSTS suggested default location (program files) even though you are using Open Rails.
MSTS was built in the Win 95 / WinXP era, when the Program Files folder was not quite as protected by the OS as it is with any version since Vista. These little two-bit installers probably are having trouble placing material inside such a system-protected location.
This is why there are special instructions on how to install MSTS on any version of OS since Vista.
http://msts.steam4me.net/tutorials/i...g_msts_w7.html
If you have no intention of using MSTS, then you might need to relocate your 4 basic OpenRails folders (ROUTES, TRAINS, GLOBAL and SOUND) to another folder outside of Program Files and then link your open rails content to that location. Then these rinky dink EXE installers will work more reliably.