Serial Key Stopped Working - Character Switch?

[Swadius]

I have not activated warband on steam prior to this.

It turns out that I've been trying to use the activation code instead of the serial key. Your recommendation that I delete the Serial key registry (since it was indeed empty for some reason), reminded me to go back to my old harddrive and looked at the registry there, and lo and behold, I found my serial key.

Thanks for your help, couldn't have done it without you.