Your PC may be infected with ad/spyware. Download & install Adaware, Spybot-S&D & run scans with them. To download - Adaware - click here - Spybot-S&D - click here. Also get SpywareBlaster -click here which blocks scum in real time as you surf. l . All the programs are freeware. Remember to check for UPDATES regularly & BEFORE scanning for the first time.