'ipconfig' is not recognized as an internal or external command, operable program or batch file. OR 'format' is not recognized as an internal or external command, operable program or batch file.

When trying to run ipconfig from a cmd window (dos prompt), I receive the following error.  This applies for ipconfig, ping, telnet, format etc.

ERROR MESSAGE:
'ipconfig' is not recognized as an internal or external command, operable program or batch file.

SOLUTION:
Go to My Computer-> right click-> Properties->Advanced->Environment
Variables->System variables and locate Path Environment Variable. Add C:\windows\system32;C:\windows\; at the
end if it is not already there.

Be sure that the path for C:\windows\system32\ matches that on your computer C: drive.
Reopen cmd window and retry ipconfig, telnet, ping, format etc.