Hi Carmyy,
It sounds like something may have gone wrong during installation, you may want to try uninstalling and installing again. Running a registry cleaner maybe helpful as well. Something like Ccleaner -
http://www.piriform.com/ccleaner/download This helps clean up temporary files, internet cache files and other files that are left behind that are no longer being used, after uninstalling.
If you don't want to try uninstalling/reinstalling, you could try a factory reset.
01.) Go to your Sims 3 folder.
-- Documents > Electronic Arts > The Sims 3
02.) Rename your current Sims 3 folder to something like Sims 3 Current.
03.) Click the Sims 3 icon to create a new The Sims 3 folder.
04.) Then copy your game saves, files and such over to the new game to see if that helps.
Hopefully this helps,
MrsFlynn