Put this two lines of code at the TOP of your macro, one to declare a variable for the Desktop filepath and one to solve for that variable.
Code:
Dim DTAddress As String
DTAddress = CreateObject("WScript.Shell").SpecialFolders("Desktop") & Application.PathSeparator
Further down in the macro you can now use
DTAddress in place of the path, just add the filename:
Code:
ActiveWorkbook.SaveAs DTAddress & "FAWU.xls"
These are the system folders that can be used with "SpecialFolders":
'Options For special folders
AllUsersDesktop
AllUsersStartMenu
AllUsersPrograms
AllUsersStartup
Desktop
Favorites
Fonts
MyDocuments
NetHood
PrintHood
Programs
Recent
SendTo
StartMenu
Startup
Templates