Cause: Your mouse pointer can be configured to trail when it is moved, which just gives it a blurring movement effect. Some people like this; others get a feeling of motion sickness. If you don’t like it, you can easily stop the behavior.
To stop the mouse trail effect, follow these steps:
1. Click Start--> Control Panel--> Mouse.
2. Click the Pointer Options tab--> Under Visibility--> clear the Display Pointer Trails check box and click OK.