Add rpcrt4 library dependency for Windows builds Remove dead Source SDK leftovers (legion, avi, unitlib, etc.) Drop unused trees that were never in the CMake product path: Legion, networksystem (used by legion), QuickTime/AVI, shell/autorun, Perforce SDK sources, sdklauncher, Workshopper, chromehtml (not used anymore), unittests/unitlib, and related headers. Strip g_pNetworkSystem from tier2 now that networksystem is gone. Win32+win64 Build.bat succeeds after the purge. Remove unicode, seems useless but I can be wrong