This may be caused by Windows not allowing the program to access the simulation's data files. It is generally indicated by an error message such as "VFP error 1". The problem is often due to Window's "User Access Control".
Try the following:
Run the program as an administrator: right-click on the program icon and select "Run as administrator".
Check the "Properties" of the folder containing the simulation files. They should NOT be set to "Read only".
If neither of these solves the problem, your virus protection software may be preventing files being accessed.
If the first one solves the problem you can change settings to cause the program to always be run with administrator priveleges: right click on the program icon, click on "Properties", open the "Compatibility" tab.
