This is maybe because of your computer has been infected by Ravmon virus. The first thing you have to do is deleting the virus by using your anti virus. Then, you can follow the next steps:
- Go to Accessories and click on Command Prompt
- Then you simply type then command "regedit" (register editor)
- Continue by changing the registry value from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- Delete checkedValue and then again create new DWORD VALUE with same name Checkedvalue with data value=1