Windows 7, Windows 8.X/10 and Windows Vista use UAC (User Account Control), which creates problems
when a regular (not-Administrator) user attempts to edit Microsoft Flight Sim files installed in the
default "C:\Program Files" folder.
The quick solution is to right click on
fsps.exe in Windows Explorer, and select "Run As Administrator".
the following two pages for more detailed information on how
to work around these and similar problems with all of your
FS add-ons in Windows Vista, 7, and 8.X: