You may use the following method, in Microsoft Windows 7, to modify the default profile and create changes in every users profile. For instance, you may add a particular shortcut, folder or file to the desktop of every single user. In Windows 7 navigate to:
C:\Users\Default\Desktop
Once you are in this directory you may place the shortcut, folder or file. Once the modification is complete any user who logs onto the computer, and creates a profile, will receive that shortcut, folder or file.
Additionally, you may use a group policy object (GPO) as an alternative solution if you have several users who need this shortcut, folder or file.
GPO Path: User Configuration\Preferences\Windows Settings
GPO Settings: Files | Folders | Shortcuts
Enjoy!