For the past six months when playing games, the mouse pointer jumps across the screen from place to place, rather than moving along smoothly. I have run virus scans using Norton Antivirus 2003 and scanned with Spybot and Ad-Aware. Changing the mouse did not fix the problem. This problem is extremely irritating when playing a shooting game such as Unreal Tournament or Counter Strike.

Since this problem wasn’t fixed by changing the mouse, we can assume it is not related to faulty mouse hardware. The first thing you should always do when encountering a problem like this is to ensure you are running the latest drivers for the hardware. I assume the mouse you are using is some sort of advanced mouse, such as a wireless or optical mouse. It is important for those types of mice to have their proper drivers installed, since they will generally not correctly function with just the generic Windows drivers. Another possibility, which you may have already explored, is the mouse has been misconfigured in the game setup. What settings could not be configured is a mystery to me, but perhaps if you play around trying to change different things to see their effect you may get lucky. The final possibility is there is a conflict between your mouse and another device. The most likely device in the conflict would be the video card, since the problem only occurs when playing games (which uses the 3D acceleration capabilities of the video card). It is strange that this problem only started six months ago, unless you installed any new hardware or software which could have caused this (or another sort of) conflict. Unfortunately it will be very difficult to diagnose and fix this problem without knowing more about the system. If you are not able to fix the problem, perhaps consider any installations or configuration changes which occurred immediately before this problem started happening and contact me again with any such information.