Hi, I've seen yesterday these new/old Worms games and I think that's a great idea.

I would like to know if is possible to register my retail copies of these games, if I own a retail version (the SoldOut edition ones).

I have the receipts too.

It matters for me, especially because in this way I wouldn't have to use DOSBox to play Worms United.

Nope! Sorry, but that's not how Steam works.

Ok. Thank you anyway.

Hi, I've seen yesterday these new/old Worms games and I think that's a great idea.

I would like to know if is possible to register my retail copies of these games, if I own a retail version (the SoldOut edition ones).

I have the receipts too.

It matters for me, especially because in this way I wouldn't have to use DOSBox to play Worms United.
If your computer is old enough to run Worms United without DOSBox, you can just run the EXE directly from the game folder in steamapps.

And yeah even if Steam supported retail, I don't think the original games even had serials to add.