I have no idea why the game freezes, it could be both software and hardware trouble causing that, and I'm no good at either of them
But when it says you are using the cd-key, it either wears of automatically after a minute or so, but usually it is also because you have an instance of the game running in the background.
To solve this, you need to close the instance running. Press ctrl-alt-del and open the Task Manager.
Under the tab 'Processes', you should find 'game.exe', which is the DiabloII game. Mark it, and choose 'end process', and you should be able to start the game again and log in.
If that for some odd reason shouldn't work, try restarting the computer and/or wait a minute or two. (But it will work) :thumbsup: