Windows doesn't allow (any more) - due to security reasons - to replace files directly in the program folder under \Program Files or \Program Files (x86).
Solution: extract the files to a different folder, e.g. C:\Temp, if available. Then select the files there, copy them with the menu over the right mouse button and paste them with the right mouse button into e.g. \Program Files\DC-Soil or \Program Files (x86)\DC-Foundation. After a securty query replacing is allowed.
Please make sure to copy ALL the files from the compressed file. Files with extension .dll might be invisible. In this case select in the View options of Windows Explorer to display hidden files.
For any program file (DCxxxx.exe) there are several DLL files (DCxxxxy.dll) with the user interface for different languages.