Hi Marissa,
Please use following methods and check if they help.
Method 1: Un-install and re-install Visual C++ re-distributable
a. Press "Windows" + "X" key and click "control panel".
b. Click on “Program” and then click “Programs and Features".
c. Find the “Microsoft Visual C++ 2005 Redistributable” program and click on it.
d. Click "uninstall".
e. Restart the computer.
f. Reinstall it from link:
http://www.microsoft.com/en-us/download/details.aspx?id=15336
Method 2: Un-install and re-install sims 3
Note: Before un-installing make sure that You have CD/ source to re-install it.
Thanks