I am afraid the reason might be your RAM of just 2 GB. When I used my old 6 years old laptop (3 GB RAM) it also took me about 3-4 minutes to load a savegame, although quicksaving took about 15-20 seconds. Try to turn all your graphics setting to very low and shut down all non essential programms (like web browser, antivirus etc). Are you playing via Steam? If so, then verify your local game cache - maybe some files weren't properly downloaded...
