Does anyone know if there is any boot cd/disk which will let me to bypass the password and login into Linux Centos.
There are no passwords available and I need somewhow to get into the system.
I would greatly appreciate your help.
Thanks in advance.

Well, I've never worked with CentOS in particular, but many linux distributions set up a second boot option labelled recovery that logs you in single user mode as root. If you see something like this when booting up try booting into it, then typing the following
passwd <yourusername> (example: passwd bob)

It will prompt for the new password, then do it again.

After this reboot the system in normal mode.

Here is a mini How To with screenshots about how to recover your password (root) under Fedora (works with CentOS)

digg.com/linux_unix/Root_Password_Recovery_Fedora_CentOS

You can try ERD Commander 2005.
http://www.pcworld.com/downloads/file_description/0,fid,25445,00.asp

This is an old post (3/06), so the person is no longer likely around.

Also, the ERD disk is no longer easily available, as Microsoft aquired Winternals, the developer of this utility. All links default to Microsoft's web page.