This could be due to a couple of reasons:

1) When the software is installed, it must be installed by an Administrator.  If you are not an Administrator on your computer, then you will need to contact your IT department to get an Admin to do the installation.  Once it's installed, you do not need to be an Admin to run the software.

2)   The license information is written to a file License.xml in the following folder:

    MecaWind:   C:\Users\{user}\AppData\Roaming\MecaWind
    MecaStack:   C:\Users\{user}\AppData\Roaming\MecaStack
    MecaLug:      C:\Users\{user}\AppData\Roaming\MecaLug

    {User} is the user name using the software on the computer.  

    We chose this folder because it's generally a folder for which the user would have Read/Write access.  Please confirm that is the case.  One indication is the date on the License.xml file, if it's not recent then the file doesn't appear to be updating.  Try opening a file in this folder and saving it, if you are not allowed to save the file then you don't have Read/Write Access.