Day of Defeat Source not Loading

Free Action

FS Member
I recently installed and downloaded the GCF files through SteamUp. Now when I click play, the game (Day of Defeat: Source) will not load. What happened?

Edit: Come to think of it, none of them are working. It either says "HL2" or "iw4mp" (For COD) has "stopped working" or they just don't even load. How do I fix this?