Computer Training Success

1. Ex boyfriend was a geek in training (IT student) and forbid me to smoke near the computer, said it messes up the hard-drive. True? Or was he jusr being an a-hole?
2. My computer is top-of-the-line and brand ******** new, but everytime I download a Messenger everything slows down and acts stupid. I have a cable modem. Is it the Messenger or something else?

Kareem