(1) i have KDE and Gnome both in my RedHat 9.0, how can i uninstall one of them by using termanal
(2) how can i install .bin files?
(3)my computer is a loptop and it's very slow, what windows manager should i use make redhat 9 faster? i heard there is one called openbox, i downloaded it but how can i install it?
(4) how can i uninstall RPM files? i tried $ rpm -e xxxxxx, but it caused some problem shows my gnome termanal has some sort of error??
(5) the last thing i want to say is ....i just installed my linux for 4 days but feel this OS slower than my XP??!! but i really use linux, is there any way i can make my linux faster? and i think KDE and Gnome makes my computer slow

You can install the .bin files by just issuing their respective file name.

e.g., you have a file called file.bin, then go to that directory and execute ./file.bin

you can uninstall packages using rpm -e xxxx command. if you are facing any problems after uninstalling then you might have uninstalled some shared libraries. please tell what is the error displayed.

you have xfce and xmian desktop environments that can make your linux run faster, but at the cost of low look and feel.

I'd suggest a "brutal" solution: Do a re-install and uncheck (or in what ever way the installation routines of redhat work) the options for Gnome / KDE, i.e. go for commandline login. Thus you won't have your drive cluttered with a lot of things you don't need, while you still have all necessary libs transferred to your computer.

ATTENTION! This will only do, if you feel ready for the command line under linux.

You can then download your GUI of choice and carry on from there.

Another alternative would be installing your openbox from the redhat discs (possibly during installation of the system), if it is included in that distro.