Virus that makes the hidden files in your thumbdrive..solution

Sometimes a virus or some malicious script makes the hidden files and folders not visible even when it is explicitly enabled.
In this case even if the user enables the Show hidden files and folders in
Tools > Folder options > View menu, Hidden files and folder does not become visible.
Fix:
First and foremost is the point that the user has enabled the Show hidden files and folder
1. Go to Tools > Folder options. This will show a folder options menu.
2. Go to View tab and select the option “Show hidden files and folder”
The hidden files and folders are displayed by this method normally. But in case some virus or script is preventing the hidden files and folders from being visible, follow the below steps:
1. Go to your Start > Run, type regedit and press enter. This will open registry editor.
2. Navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folde r\Hidden\SHOWALL
Note:
DELETE the value CheckedValue in the right window if it already there and type is REG_SZ
Now create a new DWORD value again with the same name CheckedValue.

3. Double click the value called CheckedValue, and modify its data value (DWORD Value) to 1 (0×00000001) . Close registry editor after this.

If still folder options is reverted back to don’t show hidden files and folders then it could be due to some virus still in action.
Navigate to the following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden
NOHIDDEN
In the NOHIDDEN folder, select CheckedValue and set the value to 1
4. Go to Tools > Folder options. This will show a folder options menu.
5. Go to View tab and select the option “Show hidden files and folder”


source: http://www.troublefixers.com/hidden-files-and-folders-are-not-visible/