Noob Question

The Sims is only single player.

Not sure the problem man. Bad download maybe? Just download a different version.

Mount the image,
Go My Computer
Right Click on the virtual drive and click then explore.
Search for a folder called crack maybe or reloaded,Deviance etc
Open it and replace that file with the one existing in the directory that you have installed the game.
If the game is not cracked then the problem must be the protection.
A file called NFO may help you. It should be inside the folder of the image or to the preview folder.