1. Use Grif's advice at http://forums.cnet.com/7726-6122_102-5509131.html?tag=posts;msg5509131
to scan and remove the usual hijackers and more.
2. RESET each browser to dust off any add ons. For each Browser you find how to reset (uninstall, reinstall does not remove these!) Now with Firefox defaulting to Yahoo search one more change. Select the search engine in Firefox of your choice.
I have a laptop acer aspire 4520 and I took it to the local computer service center but he did not remove all the issues on here. Windows popping up all over the place and I cannot get the Yahoo search engine off of the browser which is my main concern. I've tried going into the control panel etc. I've tried going into uninstall programs and still I cannot get it off. I installed Firefox and that won't load I had to uninstall Google Chrome because that crashed now I am getting all these ads coming through when I try to get onto the internet. Is there anyway to get Yahoo off of this computer.