Whenever I start Civ IV Complete Edition, it launches the standard game. Does anyone know what I need to do to play Beyond the Sword?

What is your method of launch?

In your install folder there should be one executable each for the base game, Warlords, and Beyond the Sword. I just created a shortcut to BTS and put it in my games folder on my desktop.

alternitively if you are using galaxy to launch games

hit the more button instead of play
in "Other" the 1st 3 options in that menu are the expansions

Thankchew. :)

Decided to try Galaxy and imported my Civ IV install, then faced that puzzling lack of a Beyond the Sword start option within Galaxy. Found it as directed by you under Civ IV -> More -> Other.

How do I start the expansions in the new gog galaxy 2 Beta Version?

I would like to know how this is done as well.

ATM not possible with the new client. It's still lacking features from the standard client, one of it it's the "More ..." menu.

But ... you can add the exe of the expansions manually. Add game manually => Search for Civilization 4 => Pick one entry of the list, which IS NOT the Complete Edition => Assign the exe of the expansion you want to start. Not a perfect workaround, but if you insist on using Galaxy, this is the way for now.

More than 18 months on & GOG Galaxy 2 still doesn't properly recognise Civ 4 Beyond the Sword. =/

Did you even look at the "Additional executables" option?

I downloaded using the backup downloaders and no galaxy. I stated put shortcuts on my desktop and I got a shortcut for each, base game, warlords, colonization, and for beyond the sword. Pretty neat,