Searches Hijacked every time - need help

HELP ! I have tried everything. Every time I try to search a website I created, Most times I get redirected to VENDARE YAHOO ERROR. Usually it says my site doesn't exist (which it does) and goes directly to 

http:// us .yhs4.search.yahoo.com/ 

I have uninstalled Firefox and Dropbox. I have uninstalled Google Chrome and reinstalled fresh. Disk cleanups. Defrags. I constantly remove cookies, check settings, manage search engines, delete search engines and Yahoo keeps coming up. I blocked BING from Explorer. Even old Explorer turns up these two errors. I downloaded Norton Power Eraser, did a full scan rebooted and still it happens. Had a friend come over and debugf everything she could find. I can't search for anything anywhere without this coming up! Beyond frustrating!  This is a total time waster and I hate having my computer invaded when I have paid for full protection all these years and am so careful. Please help me get rid of this redirecting!