I have my first game character on the imperial legion quest line. Everytime I talk to Legate Rikke, which triggers the attack on Whiterun, within about 5 seconds it crashes, before I even have time to exit the building on the front side. I have managed to sprint to the back porch exit and exit before the crash, but it still crashes in the same amount of time. I can go off and do other quests with no problem. But as soon as I go back and talk to Legate, 5 seconds and crash, everytime. I have tried to get it to work about a dozen times doing a few slightly different things like sprinting to the door, not moving, even saving and reloading right after talking to Legate. Everytime it's exactly the same, 5 seconds and crash. On the attempt where I saved it was, talk to Legate, 4 seconds, save, reboot computer, load, 1 second and crash, lol. I guess I could just skip this quest line, but if there is a known solution to get this quest to work, I'd like to know, thanks.
system:
i3 3220, 16gb kingston hyperx ram, radeon hd 7850, win 7 home premium. No mods installed, fresh install of vanilla Skyrim via Steam on a new system with fresh install of OS.