My build log
-------------- Build: ReleaseWin32 in wxMSW-3.0.2_gcc471TDM_Dev (compiler: GNU GCC Compiler)---------------
windres.exe --use-temp-file -IC:\wxMSW-3.0\wxWidgets-3.0.2\include -IC:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev\lib\gcc471TDM_dll\mswu -J rc -O coff -i E:\Test\WXMSW-~1.2_G\resource.rc -o obj\ReleaseWin32\resource.res
mingw32-g++.exe -Wall -pipe -mthreads -D__GNUWIN32__ -D__WXMSW__ -DWXUSINGDLL -DwxUSE_UNICODE -O2 -Wmissing-include-dirs -Wno-unused-local-typedefs -IC:\wxMSW-3.0\wxWidgets-3.0.2\include -IC:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev\lib\gcc471TDM_dll\mswu -c E:\Test\wxMSW-3.0.2_gcc471TDM_Dev\wxMSW_3_0_2_gcc471TDM_DevApp.cpp -o obj\ReleaseWin32\wxMSW_3_0_2_gcc471TDM_DevApp.o
mingw32-g++.exe -Wall -pipe -mthreads -D__GNUWIN32__ -D__WXMSW__ -DWXUSINGDLL -DwxUSE_UNICODE -O2 -Wmissing-include-dirs -Wno-unused-local-typedefs -IC:\wxMSW-3.0\wxWidgets-3.0.2\include -IC:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev\lib\gcc471TDM_dll\mswu -c E:\Test\wxMSW-3.0.2_gcc471TDM_Dev\wxMSW_3_0_2_gcc471TDM_DevMain.cpp -o obj\ReleaseWin32\wxMSW_3_0_2_gcc471TDM_DevMain.o
mingw32-g++.exe -LC:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev\lib\gcc471TDM_dll -o bin\ReleaseWin32\wxMSW-3.0.exe obj\ReleaseWin32\wxMSW_3_0_2_gcc471TDM_DevApp.o obj\ReleaseWin32\wxMSW_3_0_2_gcc471TDM_DevMain.o obj\ReleaseWin32\resource.res -s -mthreads -lwxmsw30u_core -lwxbase30u -lwxpng -lwxzlib -mwindows
Output file is bin\ReleaseWin32\wxMSW-3.0.exe with size 534.00 KB
Process terminated with status 0 (0 minute(s), 25 second(s))
0 error(s), 0 warning(s) (0 minute(s), 25 second(s))
NOTE: The OP seems to have copied both wxWidgets downloaded files into a single folder; I did NOT do that.
wxWidgets header/source is in
C:\wxMSW-3.0\wxWidgets-3.0.2
wxWidgets binary is in
C:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev
CB Global variable WX30
base: C:\wxMSW-3.0\wxWidgets-3.0.2
lib: C:\wxMSW-3.0\wxMSW-3.0.2_gcc471TDM_Dev\lib
Tim S.