Though Face Poser (Which comes with Source SDK, for those who don't know) won't work well with Vista, i'd still like to find out this problem with Source SDK, i have the Orange Box (HL2's, Portal and Team Fortress 2), and Counter Strike Source, but i only have two Engine Versions (Orange Box and Episode One) and for Orange Box, i have only Team Fortress 2 and Episode One, i only have Counter Strike Source and Half Life 2 Deathmatch, where is Half Life 2 and such? D:
On the XP Computer, i only have Garry's Mod, Synergy, Team Fortress 2 and Synergy installed (Cause it can play those more than anything, but it still can't play it without slowing down), and to get Half Life 2 on Source SDK's list of games to choose from, i had to install it and play a level or two to get it working (Which surprisingly, HL2 works better than all the other games)
Tl;dr: Source SDK won't show some games even though i have The Orange Box installed