Folder options: Setting “show hidden files and folders” doesn’t work after virus infection

After removing a virus from my friends machine, showing hidden files wasn’t working, whenever I set the folder options settings for hidden files and folders, to show all files, it is reverted back to hide them

I found this post that solves this problem

http://techsalsa.com/fix-the-problem-of-show-hidden-files-and-folders-getting-reset/

Steps to fix the problem:

1.    Now open registry editor and navigate to the entryHKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folders\Hidden\SHOWALL

2.    On the right side see the entry named “CheckedValue”, if the value is set to ’0′ change it to ’1′.

3.    The “DefaultValue” under the “CheckedValue” should be set to ’2′.

I followed the steps, then I was able to view hidden files