Problem in view hidden files

Problem:
User complained to me that my computer did not show my hidden files in my computer.
Solution:
First of all I check that Hidden files show or not from My Computer>Tools>Folder Options>View>Show hidden files and folders. Everything is right, but hidden files and folders can't show, that's problem. It means this computer is infected with some virus, so I install an anti-virus and remove all virus from computer and restart the computer. Now problem solve, hidden files and folders are shows now.