Cannot unhide hidden files and folders

Last week I was trying to access one of the folders in the computer (which is hidden). However I couldn't see the hidden files anymore. I've tried from the folder setting, untick the protected systems files also untick the extension for known files.

Still no good. So I asked around and they said it might be a virus. I scanned using AVG, nothing came up, so then I tried the online scanner from Kasperky. It picked up two trojans Trojan-Downloader.Win32.VB.kgf AND E-mail Worm Sober.f in RECYCLER folder.

I tried to remove them using Kaspersky Removal Tool. I also used the CCleaner and Advanced Windows Care. Still no good. I can't unhide the hidden files. Some said that I need to reformat the computer.

Is there someone can help me with this problem? Thanks.