Back to the Beginning This has happened twice and it is extremely annoying. I made my sim and my male sim and houses for them both. I played them successfully saving them. About a month after this progress (they got married and had a child and moved up significantly in their respective jobs). Then one day I double clicked on the Sims 2 and it loaded up like I had any other day and it was as if I had never even played. It was back to ground zero and my houses and sims were gone. This has happened to me twice now and it's extremely annoying. HELP!
That happens if the: 'My Documents, The Sims 2' folder is deleted or renamed. Make sure no one is deleting it and copy it to the desktop to make 'backups'.
If you have a mac, the Sims2 folder in the Applications folder should be left alone. However, in your Documents folder, there should be a folder called EA Games, and in that one, there should be a folder called Sims 2. This Sims 2 folder should be backed up occasionally, and if it happenes to you again, where all your gameplay seems to have reverted back to the beginning, then just replace the Sims 2 folder in your Documents folder with your back-up. This has saved me on more than one occassion!