To activate the cheat, you need to edit the registry.
The Thing: Cheat Codes Free Download
To do this, run regedit.exe and find the following line:
HKLM / Software / Computer Artworks / TheThing / 1.0
Create a string variable (right-click in the right field -> New -> String Value …) called DoInGameLoadSave and set its value to 1. This will activate the Save / Load menu in the Options menu. If you have problems with the Load function, try loading from the main menu.