Why does my sims 2 keep crashing?

I have had my dell laptop (windows vista) for more than 2 years now and have had no problems with the sims 2. I went to play today and as it was loading a message came up that said something along the lines of "application crashed. it will now terminate." I tried uninstalling all my sims 2 games/expansion packs and re-installing. Then when I opened the game another message popped up that said "the sims 2 has a known compatibility issue with this version of windows." So, I went to the microsoft website and downloaded "directx end user-runtime" in hopes that it would work. So far nothing has worked. Please help!!