How can I install/uninstall programmes easily in Linux (redhat9), I mean one like add/remove of windows. How can I check, how many programmes I have installed and where?

The easiest way to install a program in rh9 is to use rpm packages

- INSTALL -
rpm -i <packagename>.rpm
rom -Uvh <packagename>.rpm (UPGRADE)

- UNINSTALL -
rpm -e <packagename>

it's possible to see which package you have installed by doing

rpm -qa

and if you pipe it into a grep you can query a single package

ex.
rpm -qa | grep samba

but you should find a rpm manager somewhere in your menu under gnome or kde

just do
rmp --help for more info

you should be root to execute a package installation or removal.. just do 'su'
in a terminal and type your root passord

Great!!! But still it doesnot help much to newb linux user....some thing classified, grouped, garphical pakage like windows Add/remove programs then let me know plz.

Take a look at kpackage. (run it in the "Run" dialog)

The official way to install an application (RPM) is to use the Add/Remove Applications program that Red Hat supplies.

This application is located, in Gnome, in the applications menu at 'applications' -> 'System Settings' -> 'Add/Remove Applications'.

If the application you are trying to install/uninstall is not a Red Hat provided RPM then you are going to have to do it manually and that is going to differ from case to case.

Good Luck...