"Unable to load unicode.dll"

Every time I try to launch an Orange Box based game, e.g. Team Fortress 2, Garrys Mod; I am prompted with the error “Unable to load unicode.dll” and the game fails to launch. I have tried reinstalling these games repeatedly with no avail. All of the games worked without fail just days ago and nothing new has been installed/changed on my system since then. My computer is relatively new and I don’t think that it would be causing the problem. The specs are:

Windows 7 Professional 64Bit
AMD Phenom II 965 Quad Core
4GB DDR3 10666 RAM

Open the Steam window and right click on GMod. Then choose “Verify Game Cache” or something like that.