Solved Yahoo! home page won't open

I downloaded VLC Media Player and sense then when my Firefox browser opens to Start.Search.us.com instead of Yahoo!. I tried to drag the Y! icon to the house and tried Tools, Options, and typing the Yahoo! address but it still opens to that web page I don't want. Can someone please help?

Welcome
Nothing in the world is free. Your VLC Media player was either affected by a virus or the gift of search.com as your search engine was part of the price of using VLC.
Several things to do
If its a virus make an anti virus scan.
Download and make a full scan with malwarebytes. If it is a virus they should be able to remove it.
If that does not work try to change your default search engine.
Change or choose a search provider in Internet Explorer
Finally, what may have happened, is that you misssed the option when you downloaded VLC. Many times you have to untick a box that gives you these extra gifts.
With System Restore remove VLC. Then reinstall, very carefull read everything before clicking ok
http://www.vistax64.com/tutorials/76905-system-restore-how.html