Windows 7, folder and path name different  --  "My Documents"  or "Documents"

C:\Users\zzhang\Documents  is the correct representation and that is where Windows will find documents and some installation folders. I see that on my machine.

Windows uses junction points with names that point to real folders. So AGK should know this. Have you contacted the vendor (developers) to see if they can fix this?

.... Thinkpads_User

On my windows 7 machine I have both a c:\users\<user>\documents and c:\users\<user>\My Documents

Confirmed by using a command prompt and cd to each folder.

The contents of each is different.

Can I understand this way, one is the real folder name and one is a link to a real folder(like on symbolic link on Linux)? But even that I still confused, it makes "My Documents" like a shortcut to "Documents" , and I wonder which one is a shortcut to which. In my machine these two really just one single folder.

It is confusing and you do get multiple links to the same folder with different paths.  When a program asks for the users documents directory, Windows give it a path.  A program should use that path and not consider what it contains.

Windows has a setting for each user which is the location of their document folder.  The folder itself can use any vaild folder name.  To confuse things, certain parts of windows UI link to that folder by using a 'Documents' link.  This is what you might see on the Desktop and in the File Open dialog.  These are like Unix style symbolic links.

In Windows, folders don't have to relate to physical storage.  Desktop is not an actual folder, nether is Network, Printers, Control Panel and many other.  The 'Documents' icon you see most often is one of those icon types, it points to the physical storage path.