Show hidden files although computer is infected by a virus

You can show the hidden files by changing this entry even in a machine infected by a virus. There is another place in the registry that can use to show/hide hidden files, but when the computer is infected by a virus, it doesn't work:

+HKEY_LOCAL_MACHINE
+SOFTWARE
+Microsoft
+Windows
+CurrentVersion
+Explorer
+Advanced
+Folder
+Hidden
NOHIDDEN

In the NOHIDDEN folder, select CheckedValue and set value to 1.