Is the mouse moving sluggish, in the wrong direction, or is the cursor "snapping" to parts of the page? If the cursor is snapping to parts of the page, the likely cause is the Windows "SnapTo" feature. More information on that is available at [http://www.microsoft.com/windowsxp/using/accessibility/snapto.mspx] If the mouse is sluggish or moving in the wrong directions, the most likely cause is a pointer or touchscreen driver. If it's a laptop, make sure you have the latest version of the ALPS or Synaptics drivers. (Reply back here with your laptop model information if you need help finding drivers)