[GAMEPLAY] Game takes forever to close

Whenever the game ends, or the game window is closed by alt+f4 or other means. It does not close immediately, it takes several minutes for the game to close and to return to the client. Sometimes it is required to go into task manager. My computer specs are as follows: *Windows 7 64 bit Intel i7-4790k GeForce GTX980 16gb Corsair Vengeance Ram (DDR3) MSI z97s SLI PLUS Motherboard * If anyone can assist me that would be appreciated, thank you