recently i ve downloaded nvidia driver for fedora 8....which in order 2 install requires stopping the x server..........i have entered into the console by pressing "alt+f3" but it didnt help...........
what shud i do...am i suppose to run the fedora in run level : single user by making changes into the xorg file ...it seems quite dangerous 2 me as i am new 2 linux.....it might not switch back 2 run level 5.............what shud i do ...please help

You shouldn't install the nvidia driver like that. Just go to livna.org, grab the livna repo rpm, launch a terminal, log in as root and install it with rpm -ivh (name of livna rpm).

Once it has been installed, simply use the command yum install kmod-nvidia. Wait for it to finish and hit ctrl + alt + backspace.

actually i ve also downloaded nvidia 4m livina .everything went fine....moreover the drivers also got installed ..but even then the problem of 3d effect persists..that is not able 2 enable 3d effects...moreover the fonts are also not clear enough to see properly .............actually when the fedora starts ............it shows "building all kmod of nvidia failed".........
how is dis possible.........

There is some contradiction there, no?

As I pointed out, you go here:
http://rpm.livna.org/rlowiki/
and you download the Fedora 8 repository rpm to your desktop.
Then you open a terminal and you do:
cd Desktop
su -
(type root password)
rpm -ivh livna-release-8.rpm
yum install kmod-nvidia


That's it. Now, as for the issues you are having, those seem to be caused by not following the proper procedure. The first thing you should do is try and remove any parts of the nvidia driver that were already installed and then run yum install kmod-nvidia. However, if things go mixed up badly enough for that not to work, you may need to reinstall all of X, which is not exactly an easy thing to do. You may as well do a reinstall if you are not familiar with Fedora yet.

Enabling compiz is rather easy. If you use Gnome, just go to System > Preferences > Sessions and click on "Add". Type compiz for title and compiz for command, then log out. This is the ideal scenario but you may find that it takes more effort to enable compiz with specific types of video card (some ATI in particular).

To answer your original question about stopping the X server, after pressing [CTRL][ALT][F3], and logging on, enter "sudo /sbin/init 3". This will get you into run level three which is console based, multiuser with networking.