Hi, my name is Janak and im from india, currently studying computer science. I had got fedora core 7 mainly to practice my shell programming but i thougtht i'd put it to other use also. I do not have an internet connection on that system. Here are some of my questions.
1. i have an nvidia graphics card and the linux drivers from it but im unable to install them with the error message "your running an X server" or something close to that and some thing else.
2. its unable to play DVD due to some plugin defeciency and unable to install any new softwares saying network not available

I know how to log on as root user so please don't give me that as an option.

To install the X nVidia driver, you need to quit X first.
On my slackware system, I get out of X and into runlevel 3, as per the nVidia installation instructions, by entering a console as root or log in as root and typing 'telinit 3' at which point X is killed, and then I run teh nVidia installer.
I realize Fedora is somewhat different than Slack, however I hope this points you in the right direction.

As to the DVD issue, more info might be handy, however, if Fedora is one of those distros that searches for stuff it wants on its own, it might be looking for the DVD decrypting library 'libdvdcss' or some other component needed to play DVD's. However, I have also gotten that error using XINE on occasion, after telling it to play something from the wrong place, or from an unreadable disc.

Well, when in fedora wanting to install your nvidia drivers downloaded I presume from the nvidia website it's quite simple, and the nvidia page does describe this. Anyways here's howto:

When in the GUI .. press CTRL+ALT+F1 to go to the shell.

Then type: /etc/init.d/gdm stop (or xdm,kdm, depending on your GUI, KDM=KDE GDM=GNOME XDM=DEFAULT MANAGER!).

I presume it's GDM, since fedora is installing this by default AFAIK.

Then go to the directy where the nvidia driver is:
type: chmod +x NVIDIA-Linux-x86-x.x.x.run

then:
type: ./NVIDIA-Linux-x86.x.x.x.run
OR : sh NVIDIA-Linux-x86.x.x.x.run

BE SURE TO HAVE YOUR KERNEL SOURCES INSTALLED!!!!

Now type: /etc/init.d/gdm start (this will start the gui again!)

Next up: Playing dvd's.. Download the libdvdcss package, install it.

LIBDVDCSS HERE

It's a .rpm file, so just double click and go .