This sought of condition occurs to some PC’s when infected with virus as well, but what the virus code actually does is, it changes the registry value and nothing else. After knowing how to do this you can also deactivate that virus code easily which is the best direct troubleshooting tip for this type of virus activity on your PC.
2) From the left pane go to
HKEY_LOCAL_MACHINES -> SOFTWARE -> Microsoft -> windows -> CurrentVersion -> Explorer -> Advanced -> Folder -> hidden ->SHOWALL
3) From the right pane search for the entry “CheckedValue”
4) Double click on that which gives you ‘Edit DWORD value’ message box
Change the value data to 0 (select hexadecimal mode) and restart your PC
That’s it!! Now your hidden files cannot be accessed even after changing the folder options. If you want to get then back, follow the same path and change value data to 1 and restart your computer.
Note: Always be careful working with registry; don’t overdo anything you don’t know.