After much trial and error I found that The Sims 3 wasn’t crashing to the desktop, Windows was closing it. I installed a memory monitoring program and a mini DUMP viewer. Using these 2 programs I was able to find the problem. I had all the symptoms like slow saving game, running slow and various other issues.
After viewing the Dump file I found I was getting a 0xC0000005 Access Violation error which suggest maybe bad memory. But my memory is good. Further research led me to DEP (Microsoft‘s Data execution prevention). Don’t turn it off! Go into the setting and turn it on for all programs except the ones that you can add to the list and add TS3.EXE to it.
To access this go to Start > Settings > Control panel and select System. Click on the Advance tab and click on the settings button for performance. Click the TAB for Data execution prevention and click the option to [Turn on DEP for all programs and services except those I select] and add TS3.EXE to the list and ok it and reboot.
Hopefully this will fix your problem.
You may have to add other programs to this list that you use also because this turns on DEP for ALL programs and not just for Windows.
0xC0000005 Access Violation Link