Right click on TurboCAD desktop icon and click on Open File location

Write CMD and hit Enter button:

This  dialog  box will appear on your screen:

Write:     tcw27/clearlicense

Once your registry is cleared, you'll get the following message.

Now Launch TurboCAD again and this will give you liberty to add new license and other information.

Please add your Name, Email ID, Organization and new License Key in this dialog.