Looks like you have some sound advice already. When you have problems like this, go to the manufacturers website or call their support line and see if they have any idea what might be wrong. Sometimes the device drivers go faulty. Not sure why, its a computer, they are unstable machines, they rely on magnetic media to store info on the Hard drive, like all machines, they occasionally fail for no apparent reason. Feel free to drop me a note if you have any comp issues.