Ghost Writing

I just received a new Dell Dimension 8200 computer. I was using it this morning to write an email with MS Outlook 2002 (XP). I sat there and watched words appear on my screen that I wasn't typing. I left the computer for a while and came back to find a page full of text that magically appeared. It wasn't happening really fast, more like someone was typing phases in a chat mode and I was intercepting them. They are actual words although they do not form coherent sentences, more like a series of phrases.

At one point in the "ghost" writing the typist seemed to be referring to the movie "Pearl Harbor".

This same situation also happened when I was within MS Excel. It seems like this is some sort of crosstalk but then I think I should get special characters or gibberish, not semi-coherent words/sentences.
I disconnected from the internet and still received the "ghost writing". I then disconnected the phone wire from the wall and still it continued. It seemed like a macro or something was running.
Does anyone know what is going on... how I can prevent this from happening?

Here is a sample of the "ghost" text:

They were a new law a new I-I I’m I may a new new Hampshire a a a two I a a a E. a a a a a a a man a a show a a five five a man new a five to and I a new they man new to the long they were manner way a new a a new a a a a a a very very boring yet a oh five am a a man who a new be a new a new a man a a man a a ten a man a they do a new they a that a 5:00 AM way of all a way live man in the go man file a a a man a file a woman the new law way you do you wish to receive via file of the new a a a a way to do to the new to the new to the a file the and, the new new one of the two and file new have a man and a major the a a way to this airline I do a a a a game show a the way the a new DNA two to oh no new one with power out a man a a new power are out the new way to his five a new server I he will be one where the. Now high and all the one to hear to do the freedom new be so they were to 95 to one of the main and to move in fall.