Step 1:-
First You put any windows 8,7 or vista cd into your computer
Step 2:-
boot the computer.
Step 3:-
Click on repair your computer
Step 4:-
You’ll need to choose the correct installation of Windows and then click the Next button.
Step 5:-
And then you’ll get to the System Recovery Options screen, where you can get to the Command Prompt.
Step 7:- then type " xcopy c:\windows\system32\cmd.exe c:\windows\system32\sethc.exe "
Step 8:- Restart your computer and open windows show logon screen then press shift button 5 times.
Step 9:- then type in cmd "net user (username) (password)"
Step 10:- close cmd and type password then your computer open.
(Note:- C:\windows\system32\...... this is windows installation location when your windows intall to d drive then type D:\windows\system32\........)