If you continually get DNS errors while trying to brows any site, but the same site on another computer on the same network is working fine. Then this problem is because of the DNS cache of the machine and you need to reload your DNS cache on that machine.
Following is the process to Clear/flush DNS cache
To Clear/flush DNS cache in Microsoft Windows.
In command prompt, type
To Clear/flush the DNS cache in Linux, you need to restart the nscd daemon.
You need login into the shell of your machine and type
root@support [/etc/rc.d/init.d]# ./nscd restart
In your terminal, type
For Tiger Mac