"Show hidden files" option is not working

OK, I know this is the very basic thing that goes with Windows, but I am asking it here in search of answer.

I put my pendrive and it autoruns. This changed the show hidden files option off, I mean I am not able to see my hidden files as it is not applying the changes. What is the registry file that has modified?

I have scanned my computer using 4 antivirus programs. BitDefender found and deleted something in temperary folder. The rest didn't showed anything.

I have encountered this problem a few more times but this time I don't want to format it ;-)

Your question is a little unclear, but I will do the best I can to answer it.

In most of the recent versions of Windows there are two "show hidden files" options.

If you select "Show hidden files, folder and drives" you still will not see "protected operating system files" unless you also uncheck that checkbox. I think on XP you need to scroll down to see that one.

Here is the registry key that you can check

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)