Copy the SourceForts folder in the appropriate dedicated server folder.
C:\Program Files\Valve\Steam\SteamApps\(steam account name)\source dedicated server\SourceForts
Find the gameinfo.txt in that folder and rename the game and title from "SourceForts v1.4.1" to "SourceForts v1.4.1 DS"
Now open your Steam menu again and return to the Source Dedicated Server tool. Choose the SourceForts DS entry and modify things from there.
It's also smart to create a server.cfg file in your /cfg folder. Mine looks like this:
- mp_build_longtime 20
mp_build_shorttime 8
mp_build_alternate 2
mp_fight_time 15
mp_ctf_autoreturn 45
mp_build_melee 0
mp_freeze_max 8
mp_damageable_pieces 0
maxplayers 8
mp_timelimit 81
log on
Once you have created your server.cfg file and chosen all the options in the Dedicated Server Tool, start the server. Once it starts, go to the console and type "map (mapname)" to start the first map. The "map" command drops everyone from the server, so you should only use it when you first start the server. Any other time you want to change maps from within the console, use the "changelevel (mapname)" command, all sans quotes.