Hello folks

I bought Warband via the Taleworlds website many years ago. This order was processed by Avangate, who are apparently the 'authorised vendor of Taleworlds products'.

I still have my serial key.

Is there any way I can activate this on GOG?

I suspect not, because the Reclaim pages here at GOG mention Russian/Starforce versions of the game.

But I thought I'd ask just in case!
Is there any way I can do this?

Thank you

Did you try using your serial key on the reclaim page?
It's worth a try to try reclaiming your game. You won't lose anything and if it doesn't work then you at least found out.