Search.us.com comes to your browser usually from downloading/installing free program. It will change your default search engine and homepage of your browser.
To remove Search.us.com from Mozilla Firefox :
• Uninstall Start.search.us.com programs from your Windows
• Go to Control Panel--> Programs and Features
• Look for Search us com and uninstall it
• Go to Control Panel--> Programs and Features
• Look for Search us com and uninstall it
• Open Mozilla Firefox browser
• Type in address bar: about:support then click Ok or Enter
• See the Reset Firefox to its default state window (at the right), then Click Reset Firefox button
will be a warning Are you sure want to reset firefox to its initial state ? Click Reset Firefox
• Restart Firefox, and see the result..