Hiya :) there are grey and black glitches everywhere when playing my sims 3 game. anyone no how to fix it?.?

the game was running perfectly on my new hp laptop until i had to send it away for repairs due to a faulty hard drive. anyway my hard drives been replaced and iv decided to reinstall my sims 3 late night and world of adventures. its virtually impossible to play due to terrible glitches in the graphics almost cannot see anything at all sometimes. very confused as to why it is like this as the game ran so perfectly before. any help would be brilliant. thank you :)