I keep getting the following 2
 

I keep getting the following 2 critical errors when trying to instal OpenFOAM-1.5

gcc 4.0.3
WARNING: Conflicting installations:
OpenFOAM settings : /home/shuo/OpenFOAM/ThirdParty/gcc-4.3.1/platforms/linux/bin/gcc
current path : /usr/bin/gcc
CRITICAL ERROR

gzip 1.3.5 /bin/gzip
tar 1.15.1 /bin/tar
icoFoam
WARNING: Conflicting installations:
OpenFOAM settings : /home/shuo/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/icoFoam
current path :
CRITICAL ERROR

I have installed it in $Home/OpenFOAM and when i sournce the bash script >> . $HOME/.bashrc it tells me to modifiy WM_COMPILER_INST setting to 'System' which I did.

The bash script shouldn't tell
 

The bash script shouldn't tell you to use the system compiler unless you have modified the scripts. Have you made any other modifications than changing "WM_COMPILER_INST" to "system"? Can you run "icoFoam" without any problems?

I would recommend using the c++ compiler provided in the OpenFOAM package. That's if you plan to make any mofications.