Start >> Run >> (type) regedit >> (rightclick on the little my computer icon, and export the whole thing.)

find this key: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced.
Go to the rightside of the window, where the values are. Find the value "Hidden" .
Rightclick it and modify it to 1.

User Key: [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
Value Name: Hidden
Data Type: REG_DWORD (DWORD Value)
Value Data: (1 = show hidden, 2 = do not show)