There are several directories under my Program Files that are visible in the Open File dialog of any program, and you can open those directories and look inside and right-click them and do the normal stuff. But they are not visible in Windows Explorer (even if you set Folder Options to show hidden files and show protected OS files), and not visible on the command line with "dir" under any options or any other command. If you try to manually enter the location in Explorer or the command line it will tell you the file does not exist.

After poking around, I enabled the attributes column in the Open File dialog and found out that the relevant directories have the "N" attribute. This attribute letter is not listed in the help pages of the "dir" or "attrib" commands; and after much searching on the Internet, I found that it refers to the "Not Content Indexed file attribute".

Another thing is that these directories all belong to programs that I have recently uninstalled (the remnants of what the uninstaller didn't remove is what is inside).

What is this attribute? And should I be concerned? Why can I not see or do anything with them anywhere except in Open File? This is not malicious activity or anything right?

See the following thread - it explains what the file attribute with the N switch is all about in Windows Vista explorer.

http://www.vistax64.com/vista-gener...

For threads dealing with not content indexed file attribute click on the following M$ website search results:

http://search.microsoft.com/results...

i_Xp/VistaUser