Win8 command prompt CMD command invalidation how to do

Symptom:
After entering the command prompt state, no matter what DOS command is executed, it is prompted: "XX is not an internal or external command, nor is it a runnable program or batch file", as shown in the figure:
< Br>Cause analysis:
This problem is caused by some software modifying the value of PATH.
Solution:
1. Find the “Computer” icon on the desktop and click the right mouse button, and select “ldquo; Properties” in the pop-up menu. 2. Click on the left side. ;Advanced System Settings>;

3. In the pop-up system properties dialog box, click the “Environment Variables” button;

4, find the variable “Path” and click “Edit & rdquo; button;

5, modify the variable value is "%SystemRoot%System32;%SystemRoot%System32WindowsPowerShellv1.0", and finally click the "OK" button to end the setting;

6, restart your computer.