To save 5K go to the following key in Regedit:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Tips
Now simply delete these tricks by selecting and pressing the DEL key.
Change the Default Locations
To change the default drive or path where Windows will look for it's installation files, go to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath
Now you can edit as you wish.
Secure your Desktop Icons and Settings
You can save your desktop settings and secure it from your nerdy friend by playing with the registry. Simply launch the Registry Editor go to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
In the right pane create a new DWORD Value named NoSaveSettings and modify it's value to 1. Refresh and restart for the settings to get saved.