Two lines appearing on lap top screen

[Curitiba]

Hi, since I started using public internet access with more frequency (about two months now), I noticed a line through my lap top screen. Last night there were two lines - what is that?
How can I fix it?
Could it be because of internet sharing facility? Have I been hacked?
Please help me!

[ethandron]

It could be a virus. I seem to remember an old one that added dark lines until you can not see the screen at all.
Do you have any anti-virus software?

[Curitiba]

Yeap, I've got Norton. Did two full checks already and no virus/trojan/tracking software found.

Help!