I have a similar problem. I finished pre-loading the game, restarted steam, and as soon as the decrypting finished steam started "updating" the game with a 5 gb update, basically restarting the install. I know the first install worked because I'm able to run the game directly with the tesv.exe in the steam folder. I don't want to go through the whole install process again because my download speeds are very slow. Honestly, my problem seems like a steam problem, but the steam forums are down so I can't ask for help there
