From the desktop, Right click 'Computer', click 'Properties'
     then click 'Advanced system settings' 
            - this should bring up the System Properties - Advanced tab
Click 'Enviornment Variables'
Select the system variables 'PATH'
Edit PATH and add this line to the front
        c:\windows\system32;
or to be generic (in case you've installed windows on a different drive)
        %SystemRoot%\system32
Start a new command window to check if this has worked (or reboot)
      existing command windows will use the old path