Not sure where this dll is supposed to be, but during compile I got this error:
uforadiant.exe - cannot find component.
This program could not be started because libgdk-win32-2.0-0.dll could not be found. This problem might be fixed by reinstalling the program.
Checking for existence: C:\Program\UFO-SVN\radiant\uforadiant.exe
Executing: "C:\Program\UFO-SVN\radiant\uforadiant.exe" (in C:\Program\UFO-SVN\radiant)
Process terminated with status -1073741515 (3 minutes, 28 seconds)