Here's my problem. My parent's computer is continually getting Application Error pop up messages. The error reads: "The instruction at "0x000000000" referenced memory at "0x00000000". The memory could not be "read". Click OK to terminate program." It seemingly has no pattern as to the programs it effects. It has effected bootup files (logonui) and application files (word) and installation files (setup). Thinking it was a virus of some sort my dad bought Norton 20004 Professional. After doubtfully installing it. I attempted to run it and the program won't even open. Please help as much as possible.