http://www.microsoft...&DisplayLang=en
After you install it, reboot your computer. If this doesn't solve your problem, then it may be that the 'Media Sense' feature is causing you issues. To learn more about Media Sense, and how to disable Media Sense, visit this website:
http://www.michna.co...xMediaSense.htm
If you're still having problems, then you may wish to look at your hardware.