• Game Save Manager [www.gamesave-manager.com]

This is a program I recomend,it's totally free and it basically searches your computer for all of your save games and let's you back them up or delete them.

First Step
Uninstall the game,make sure the whole folder is deleted from the folder you installed it in.
Second Step
Open Game Save Manager (assuming you already downloaded and installed it) and let it search all the games, click on the blue "Make a backup" under the "Backing up..." name.
Third Step
Search for the Metro 2033 Redux name and click on it,once you do your saved game will be selected.
Fourth Step
Click on the red cross button on the middle of the three buttons on the right top side,this will delete your saves.
Fifth Step
Now that you deleted the saves close Game Save Manager,redownload the game and it should now work!