SETGPC.BAT does not allow me to compile C using gpc: gpc tc.c -o tc As installed by dev_gnu_pascal-1.9.4.13.exe, SETGPC.BAT: set PATH=C:\prg\GPC\bin;%PATH% set C_INCLUDE_PATH=C:\prg\GPC\include set GCC_BASE=3.4.5 set GPC_EXEC_PREFIX=C:\prg\GPC\libexec\gcc\mingw32 set LIBRARY_PATH=C:\prg\GPC\lib;C:\prg\GPC\lib\gcc\mingw32\%GCC_BASE% set GPC_UNIT_PATH=C:\prg\GPC\lib\gcc\mingw32\%GCC_BASE%\units;C:\prg\GPC\units;C:\prg\GPC\units\winapi;C:\prg\GPC\units\objects;C:\prg\GPC\units\sysutils;C:\prg\GPC\units\objmingw I have been able to compile and link Pascal and C (one each) by only changing PATH. Separately, I succeeded by appending c:\prg\gpc\lib\gcc\mingw32\3.4.5\include to C_INCLUDE_PATH. (After running SETGPC.BAT) I don't know what to say is wrong. The lack of a trailing slash on GPC_EXEC_PREFIX results in a horrible mess in one of the attempted directories (C:/prg/GPC/libexec/gcc/mingw32mingw32/3.4.5/../../../../include/stddef.h) but appending a slash doesn't solve the real problem, because "libexec" is the wrong path to get to an include directory. Does GPC have different rules for the EXEC_PREFIX than GCC, so the lack of a trailing slash is not a mistake for GPC_EXEC_PREFIX? Does the setting of all of the variables other than PATH date back to a time before GPC did such an elaborate job of fabricating directory names? Or before GPC had the target and version wired in? Is it likely that all I need is to prepend GPC/bin to PATH? Or do you think I will need some of the other environment variables when I get around to trying to compile more substantial programs?