when I open a blank tab, Yahoo has hijacked the new tab with its search thingie, how to remove?
I have removed all search engines except google on the search bar. When I open a new "blank" tab Yahoo search is the page it opens, I can't find how to remove Yahoo.
Check your extensions, one of them is likely to have made this change. Also see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.