my os is corrupted
 

i am using redhat linux.somehow it got corrurted and i can't find os dvd .any easy method to make it functioning again as i am still a student

What does "it got corrupted" mean?

There are numerous CDs you can download to correct problems. In addition to a response to the question posed by MTK358, it would be helpful if you indicated which distribution and release you are using.

Why don't you do a little diagnosis, and try to find out what went wrong, and fix it? Unlike that other OS, the remedy for most problems it not to re-install everything.
What, very specifically, is the problem(s) that you are experiencing? What happened immediately before the problem started?
--- rod.

If it's Red Hat, presumably you have contacted their support team as per your licence?

Welcome to LQ :)

wanna upgrade my os to support gui
 

actually by corruption ,i meant that i installed redhat linux in text mode as my laptop's graphics card didn't support it in gui. now having downloaded required drivers from nvidia's site ,can i now upgrade my os to gui but i can't find any os cd now?

You installed in text mode means you did not install X? Or does it mean you used text mode to install but installed X applications? And I would not call this OS corruption. Nothing has happened to your OS. If you did not install X or your graphic card is not supported and you can not get to GUI, you need to fix it not reinstall OS.
If you have downloaded the drivers, install the them. And then install X if you have not. If you do not have media, use yum to install from internet. You can use CentOS5 repositories if you do not have RH subscription.

Your OS is perfectly fine. You just don't have the necessary packages installed and configured.

You shouldn't have had to download the Linux drivers manually from NVIDIA's website...IIRC Red Hat/CentOS (well, dunno about CentOS) have the NVIDIA graphics drivers in their online software repositories. You should just be able to do a yum install <whatever the NVIDIA driver package is called> and it'll download and install the drivers for you, no CLI messing necessary.

EDIT: What model video adapter is installed in your laptop? I hear that NVIDIA has stopped (or is going to stop) supporting legacy hardware.