fuzzybrownie

I have problem and need help. I've taken a new job and rec'd an old laptop. Every once in a while (3-4 times a week) - as I'm on-line, an adult website pops open and starts loading other adult websites with new windows. I have cleaned out the history and temporary internet file - (which gets rid of my cookies of sites I need). But this still happens - and it is the same website like [url]3w's then:66.230.134.150. I need to be on-line for work and this could be very embarrising if a co-worker is with me at my computer when this happens. Does anyone know where else on my computer I need clean out or what else I can do? I don't know too much about computers, so please repond as if i was a novice to the inner workings of computers - thank you very much for the answers so far