Linux 5 is not detecting my broadband modem

<span>In a recent days in our lab I've got a with Linux file system. <span> </span>Our lab used Redhat Linux 5.3 Enterprise version. Redhat Linux is an Unix based Operating System and It based on Ext3 file system</span><br /> <span></span> <br /> <span><span>Problem of Linux:<span> The systen cannot access internet. It shows the license expiry error notification. Some</span></span><span>time it doesn't detect the hard drive. Some time the pc can detect hard drive but the Linux started with some errors of file system. Finally the file system of the OS getting crashed and can't boot. At GRUB loading stage it become restarted.</span></span><br /> <span><span></span></span> <br /> <span><span><span>Solution or Troubleshooting: </span><span>If I replace the hard drive cable It detect well and start OS also. Then the pc can detect hard drive but the Linux started with some errors of file system. Then I discovered that there is a problem with OS.<span> </span>Though formatting can solve the problem but that needs a backup of important data. This is time consuming and risky. So I thought to repair the file system</span>.</span></span><br /> <span><span><span></span></span></span> <br /> <span><span><span>At first I'm trying to login in single user mode and repair the file system. I have tried to login by pressing "s" beside kernel at startup in single user mode. But the system doesn't boot. Then I'm trying to repair the OS by RedHat Linux CD. I <span> </span>Insert the CD and select rescue mode by pressing "F5" key. Then I got the single user mode. After that I check all file system sequentially. </span></span></span><span><span><span>/etc /passwd, /etc/shadow, /etc/securetty, /etc/pam.d/login. Those file was wrong. I updated those file by correcting. Then I update the auth config file. After that I boot the system again. But now also it don't get start. Then I rescue the grub by grub-rescue and also update the kernel. After the total process I'm tried again to login from single user mode in root and It get logged. After that I reboot the system and tried to login. Finally it logged in successfully and run properly.<img src="alokerdas.jpg" /></span></span></span>