When a user logs on to Windows 7 for the first time, there are some tasks that need to run. Be modifying the default profile, you may inhibit those actions from running. Below is a list of potential problems.
- Their list of most frequently run programs is not cleared
- Whether the user has been introduced to the Start menu (will be set to TRUE for the source account, but should be FALSE for new users). Windows Explorer does some special things the first time you log on to introduce you to the Start menu and other new features.
- Whether the user is an administrator (and should therefore see the Administrative Tools, etc).
- The personalized name for “My Documents” will be incorrect. All users documents folders will be called “Administrator's Documents”. This is documented in the Knowledge Base article “The Desktop.ini File Does Not Work Correctly When You Create a Custom Default Profile” (http://support.microsoft.com/?id=321281).
- The default download directory for IE will be set to the Administrator's Desktop folder.
- The default Save and Open locations for some application with point to the Administrator's documents folder.
- Windows 7 Libraries are broken.
By manually modifying the default profile (or via a script) you are placing your Windows deployment into an unsupported state. Not good. Go to this article and take a look at option B. Note, that there are drawbacks to Option B. I support option F, Group Policy.