VCOMM Error:OE: 0028

I get a blue screen with this message. I get it on different occasions. I don't have to be on the internet. When I get the message all I have to do is hit the enter key and I am returned to the task I was doing. I cannot duplicate my actions to get this blue screen but about 25% of the time I'll get this message when the screen saver is active (blank screen selection). Again, All I have to do is hit the enter key and the sceen saver will return. Yesterday was different. I was editing an Excel 97 document when I got the blue screen. I hit enter and the computer rebooted! Help!

Craig