I followed the instructions in the manual and successfully built and installed gcc3.3. Problem occurred when I tried to compile C/C++ src with gcc3.3. Details are given below: System: Red Hat Linux 7.2, P4 server Because this version of linux ships with the defective gcc 2.96, I tried to install gcc3.3 for myself. So the new gcc is not installed in the default /usr/local directory since I don't have root privillege. I installed gcc in a directory different from the gcc source directory, as recommended in the installation manual. I strictly followed the steps in the manual. Successfully built & installed gcc. The new gcc can now compile some simple programs without header files. When I tried some real programs, a lot of errors reported in compiling process. Most of them were reporting that there are errors in the header files. I found those incompatible header files were in /usr/include, so I guess they were the header files of gcc2.96. I then tried -I/-I- directives to give the specific path of the new gcc include directory. I also put the new gcc paths in the beginning of PATH env varible. But the problems remained. The new gcc was still unable to find the correct include files. Could anybody tell me what I need to do to properly configure gcc3.3 after installation ? Especially how to solve this header file problem. Thanks a lot!