keyboard malfunction etc. when on internet

I have an HP Pavilion and Windows XP. When I'm connected to the Internet, after a while the keyboard malfunctions--e.g., instead of copying and pasting text, it does a screen print image. And then other malfunctions take place too--caps intstead of lowercase letters, ctl and alt keys responding incorrectly, etc.

My local computer guru thinks that this may be a sign of an old motherboard, which would need to be replaced.

Is it possible that this is a less serious problem? Thanks in advance.

 

It's possible, check out this post.
http://forums.majorgeeks.com/showthread.php?t=206351