If it is Linux, then you must ‘ifconfig’ and not ‘ipconfig’. Also, you must have root priveleges to do so. Either log in as root, or use ‘sudo’ (Super User DO) command to run it with root user priveleges. In second case too, you must supply the password once! If it Windows, then you should try to get the ‘ipconfig.com’ file,which is just like a binary ‘.bin’ file in Unix,Linux, and copy-paste it to your C:\windows\system32\ folder in case of windows XP, and to C:\windows\system\ folder in case of windows 98 SE. Try it, it should work.