This Program will save you the trouble of editing the registry
yourself.
It will not work if you do not have MSTS trainsim installed.

cdfix - removes the cdpath value
default - as it came
small   - 640x480 screen size
medium  - 800x600 screen size
Special - 775 x 628 large screen size
also changes the max value to "1" or "0" as explained by JohnCS.
AE fix - deletes all of the AE keys to return it to normal

NOTE: 
   1.1024x768 will fill your screen if it is set to 1024x768 already,
you should be at 1152 or larger to use this size.
   2. No longer checks for directory, it checks the registry.
   
   jtsdadinaz@hotmail.com