the "savegame" data are stored in the windows registry
HKEY_CURRENT_USER\Software\DeGenerals\TankMechanicSimulator

Windows-Key + R and type in : regedit
and then choose the mentioned branch or copy paste it in the address-bar on top of the registry editor.
Right click the "TankMechanicSimular" in the left tree and choose "export" to save it somewhere else. Later you can just right-click that file and select "merge" to copy its content in the windows registry. But I´m not shure if this will work correctly on another computer - registry is sometimes a bit strange and it´s definitely not a place where a user should play around - its also not a place where someone should store savegames...