Nothing wrong with your system. The cited folder gets ripped from the AIOI and substituted with the models folder you'll find in your Documents folder. The version of the AIOI you're using can be identified via the installed progs or the "Setup Log.txt" you can find in:
C:\Windows\LDraw
In the log you'll also find confirmation if a file has been installed or not.
w.
C:\Windows\LDraw
In the log you'll also find confirmation if a file has been installed or not.
w.
LEGO ergo sum