In Vista when the user places the mouse pointer over a particular icon on the desktop, a tool tip pops up. This tool tip displays information about the icon.At a particular time, you might already know what each icon on your screen represents and hence the information might be unnecessary.
If you feel you no longer require tool tips, you can use this simple registry tweak to disable it. To do so:
On the right pane, click the “ShowInfo Tip” registry key.
Click “Edit | Modify”.
Change the value to “0” in the “Valuedata” field.
Close the registry editor window and reboot your system for the changes to take effect.