Dear David, I gave the following and pressed TAB, it seems that i have two python installation in my linux. $ python python python2 python2.2 python2.4 pythonsh When i give python, python 2.4.3 interpreter opens When i give python2, python 2.2.3 interpreter opens The default is python 2.4.3. Now when i use 2.4.3, i get the import error but when i use 2.2.3 i dnt have the import problem. When i give *ls -d /usr/lib/py** ( i get only the lib for pythong2.2) */usr/lib/python2.2* I dnt understand why python 2.4 dosent contain seperate libraries installed in /usr/lib? The following is the result of the command - python -c "import sys; print sys.path" ['', '/usr/local/lib/python24.zip', '/usr/local/lib/python2.4', '/usr/local/lib/python2.4/plat-linux2', '/usr/local/lib/python2.4/lib-tk', '/usr/local/lib/python2.4/lib-dynload', '/usr/local/lib/python2.4/site-packages'] ----------------------------------------------------------------------------------------------------------------------------------- OUTPUT OF env command MANPATH=/usr/local/ifc/man:/usr/local/ifc/man:/usr/local/ifc/man:/usr/kerberos/man:/usr/share/man/en:/usr/share/man:/usr/X11R6/man:/usr/local/man SSH_AGENT_PID=1970 HOSTNAME=bala_lin PVM_RSH=/usr/bin/rsh INTEL_LICENSE_FILE=/usr/local/ifc/licenses:/opt/intel/licenses:/home/souvik/intel/licenses:/usr/local/ifc/licenses:/opt/intel/licenses:/home/souvik/intel/licenses DESKTOP_STARTUP_ID= TERM=xterm SHELL=/bin/bash HISTSIZE=1000 GTK_RC_FILES=/etc/gtk/gtkrc:/home/souvik/.gtkrc-1.2-gnome2 WINDOWID=25165899 QTDIR=/usr/lib/qt-3.1 USER=souvik LS_COLORS=no=00:fi=00:di=00;34:ln=00;36:pi=40;33:so=00;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:ex=00;32:*.cmd=00;32:*.exe=00;32:*.com=00;32:*.btm=00;32:*.bat=00;32:*.sh=00;32:*.csh=00;32:*.tar=00;31:*.tgz=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.bz=00;31:*.tz=00;31:*.rpm=00;31:*.cpio=00;31:*.jpg=00;35:*.gif=00;35:*.bmp=00;35:*.xbm=00;35:*.xpm=00;35:*.png=00;35:*.tif=00;35: LD_LIBRARY_PATH=/usr/local/ifc/lib:/usr/local/ifc/lib SSH_AUTH_SOCK=/tmp/ssh-zHIO1917/agent.1917 PVM_ROOT=/usr/share/pvm3 SESSION_MANAGER=local/bala_lin:/tmp/.ICE-unix/1917 PATH=/usr/local/autodock/share/bin:/usr/local/autodock/i86Linux2/bin:/usr/local/ifc/bin:/usr/local/autodock/share/bin:/usr/local/autodock/i86Linux2/bin:/usr/local/ifc/bin:/usr/kerberos/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/usr/local/amber9/exe:/usr/local/ifc/bin/:/usr/local/gromacs/bin:/usr/local/fftw/bin:/usr/local/vmd-1.8.6/lib:/usr/local/vmd-1.8.6/bin:/usr/local/pass:/usr/local/nab-5.0/bin:/usr/local/RealPlayer/plugins:/usr/local/mmtsb_toolset/perl:/usr/local/mmtsb_toolset/bin:/home/souvik/X3DNA/BASEPARS:/home/souvik/X3DNA/bin:/usr/local/modeller-9v2/bin:/home/souvik/bin:/usr/local/amber9/exe:/usr/local/ifc/bin/:/usr/local/gromacs/bin:/usr/local/fftw/bin:/usr/local/vmd-1.8.6/lib:/usr/local/vmd-1.8.6/bin:/usr/local/pass:/usr/local/nab-5.0/bin:/usr/local/RealPlayer/plugins:/usr/local/mmtsb_toolset/perl:/usr/local/mmtsb_toolset/bin:/home/souvik/X3DNA/BASEPARS:/home/souvik/X3DNA/bin:/usr/local/modeller-9v2/bin MAIL=/var/spool/mail/souvik PWD=/home/souvik INPUTRC=/etc/inputrc XMODIFIERS=@im=none LANG=en_US.UTF-8 LAMHELPFILE=/etc/lam/lam-helpfile PYTHONHOME=/usr/local/lib_LINUX-rh9/ GDMSESSION=Default SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass SHLVL=2 HOME=/home/souvik GNOME_DESKTOP_SESSION_ID=Default LOGNAME=souvik LESSOPEN=|/usr/bin/lesspipe.sh %s DISPLAY=:0.0 GRACE_HOME=/usr/local/grace G_BROKEN_FILENAMES=1 COLORTERM=gnome-terminal XAUTHORITY=/home/souvik/.Xauthority _=/usr/bin/env