Follow below steps if you received this error when performing any commands in command prompt.
Right click "My Computer" and click "Properties". Click the "Advanced" tab up top followed by the "Environment Variables" button at the bottom. In the 2nd list box, scroll down to the 5th or 6th entry "Path", select it and click "Edit". Add "%SystemRoot%\system32;%SystemRoot%;" (minus the quotes) to the beginning of the line. Okay the changes and try out your commands now.
