Don't know what virus protection software you use, but microsoft's security essentials is pretty good, if you want to try it. It's a free download, and works with windows xp with service pack 3, vista, and windows 7. You have to uninstall any other virus protection software first before trying a new one. I also have issues with my wireless mouse and keyboard, causing similar symptoms to yours. My mouse has a limited range of less then 3 feet. If I move it closer to the usb optical receiver, it works better.