After you plug in a Universal Serial Bus (USB) mouse, a yellow exclamation point may appear next to your PS/2 mouse port in Device Manager. When this occurs, the PS/2 mouse port has a status of "Code 24."
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
Note that the symptom described in this article does not impair the functionality of the mouse.
Article ID: 257514 - Last Review: Jun 19, 2014 - Revision: 1