Often because of a virus attack the Show Hidden files and Folders option in Folder Options of Windows does not work creating a big problem for those who have to keep many files hidden on their computer. I faced this problem many a times and often I had to format my PC.But now you dont need to worry the problem can be solved by making simple registry changes as shown in the following methods:

Method 1:

Go to registry editor by running regedit in the run box.
Go to this key:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\Advanced


In the right hand area, double click hidden and change the value to 1.

Now you’re all set to go. Check it in your tools menu if the changes have taken effect.


Method 2: (By Random Hajile)

1. Click “Start” -> “Run…” (or press Windows key + R)
2. Type “regedit” and click “Ok”.
3. Find the key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\SHOWALL
4. Look at the “CheckedValue” key… This should be a DWORD key. If it isn’t, delete the key.
5. Create a new key called “CheckedValue” as a DWORD (hexadecimal) with a value of 1.
6. The “Show hidden files & folders” check box should now work normally. Enjoy!

Method 3:

If none of the above methods work, please download our Smart Antivirus from here:
http://technize.com/2008/01/22/smart-anti-virus/
Using this antivirus, please restore your Windows settings and your show hidden files and folders will be set to default.

[Thanks Sumit]