I think spyware is acting in ur PC ..may be it comes 4m internet while u r surfing..& now its affecting registries also..u should fully scan ur PC & delete any spyware threat if found any.. & also scan for distorted regs...!! There is this one application named Advanced System Optimizer..its tool System Protector helps u in scanning & deleting spyware & Registry Cleaner & Optimizer for cleaning distorted regs..try it.. i m also using it for regular maintenance for my PC..!! It also contains some other useful cleaners & optimizers that can fix ur PC & increase its performance..!! dis is da best cleaning tool i used so far..!!
It is available at Cnet site.