I didn't play for 1-2 month and after that the game was slow (20 FPS with the lowest settings). For me solved this the problem: I had a "Selective startup" in windows. After i switched back to "Normal startup" in MSCONFIG.exe--->General tab---> switch to NORMAL startup---> click OK and Restart. Only EXPERIENCED user should edit MSCONFIG!!! I hope this will solve the problem for many users!