If the ipconfig is not working, then it is due to path variable missing in your computer.
Please follow these steps to fix it.
1. Open the Start-Menu
2. Right click on ‘Computer’ and click ‘Properties’
3. Click ‘Advanced System Settings’ on the left hand side
4. Click ‘Environmental Variables’ at the bottom of the screen
5. Check for ‘Path’ in the list. If it is present,
a) Click ‘Edit’
b) Go to the end of the text box and type the following (without quotes): “;%systemroot%\system32″
5. Click ‘new’ button,
a) In the next window, enter the variable name as “Path” (without quotes).
b) Enter the variable path as, “;%systemroot%\system32” (without quotes).
6. Click ok and close the windows.
Now open a new command prompt and type ‘ipconfig‘, it should work fine!