1. go to run(winkey+R).
2. type regedit.
3. go that path:- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\
4.Look at the CheckedValue key( in right side).This should be a DWORD key. If it isn’t, delete the key. Create a new key called “CheckedValue” as a DWORD (hexadecimal) with a value of 1.
5. now u open the hidden file and folder.