@Byblos,
even if you don't click "yes" to some strange popup windows,
sometimes the virus can install utself
when just visiting a website.
my point is, you don't even SEE anything happening while something can install itself in your system!
And if you don't have a firewall, then the possiblity that someone fooling with your pc, by installing a trojan horse is pretty real.
i suggest that you do an online virus&security scan first.
http://security.symantec.com/sscv6/...amp;amp;close_parent=true&bhcp=1
check for spyware : http://www.lavasoft.de/

Carpe diem, quam minimum credula postero