I found this on www.gamespot.com) and tried it. IT WORKS!

Locate your Emperor's Tomb folder (example path C:Program FilesLucasartsIndiana Jones And The Emperor's Tomb)
From there, open the game data folder, followed by the folder marked indy. Finally, open up the file vars.CFG, and at the top of the file, change aiDisabled so it reads as: aiDisabled=true. Once this is done, save the file and enter the game, your enemies are now oblivious to your presence and will no longer attack you