This article was previously published under Q282753
If you have a laptop computer and you are using a PS/2 wheel mouse, you may encounter erratic behavior with the mouse, such as the cursor jumping all over the screen; however, the built-in touchpad may work fine.
This problem occurs because wheel mouse devices may be incompatible with some laptops, unless the laptop has special hardware to handle them. The wheel mouse transmits in 4-byte packets, while the internal touch pad transmits in 3-byte sequences. PS/2 devices are designed in such a way that the operating system may not be aware of an additional pointing device, nor of what the packet boundaries are between the different devices.
If the operating system interprets the packet alignment incorrectly, it may misinterpret data, thus causing erratic movements and clicks.
To work around this problem, create a hardware profile in which the mouse is enabled and the touchpad is disabled.
For additional information about hardware profiles, click the article number below to view the article in the Microsoft Knowledge Base:
225810 How to Create a Hardware Profile on Windows 2000-Based Computers
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
This problem was noticed in the Fujitsu Lifebook C Series, model c-6547, and the Dell Inspiron 3700.