How to Activate -Hide protected operating system files- from Folder Option in WindowsXP

Sometimes , in Folder Option of Windows XP , due to some virus , after making change in the folder option , it wont change . I tried to uncheck the "Hide protected operating system files" from folder option, but it wont after i apply it .


To activate "Hide protected operating system files" from folder option,

Go to Start -> Run
Type : regedit and press OK .

Find :
My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\SuperHidden

find the "CheckedValue" and double click it and change the "Value data" to "0"

Done.