New
#11
When all else fails, delete all the folders on the hard drive relating to SIMs 3, including in appdata and saves (probably under folders called EA), there will be a folder in program files (x86)\EA.
To complete the job, back up the registry first then open regedit and search from the top level for EA, if you have any other EA games you may have to be careful what you remove, but anything reletive to the Sims can be deleted (or just export elswhere for now).
Ultimately go to the program removal tool in control panel and try the ununstaller from there, if and I hope it does, say the programs uninstaller cannot be found, do you want it removed from the list, yes, yes. yes, oooooh yes!
Thats job done.
If you need further help doing any of the suggested, please post again I will point you in the right direction.