That one was done with a Microsoft update that incorrectly updated people not using Bing.

How to Remove Bing as Your Default Search Engine and Get Firefox to Work the Way it Used to | eHow.com

http://www.ehow.com/how_5196325_remove-firefox-work-way-used.html

http://kb.mozillazine.org/Keyword.URL

Removing the Search Helper Extension and Bing Bar | Troubleshooting | Firefox Help

http://support.mozilla.com/en-US/kb/Removing%20the%20Search%20Helper%20Extension%20and%20Bing%20Bar

Make Google.com or any other page your home page

https://support.mozilla.com/en-US/kb/How+to+set+the+home+page

Tools > Options Security

[x] Warn me when sites try to install add-ons

[x] Block reported attack sites

[x] Block reported web forgeries

Bring up the Control Panel, under Programs and Features, uninstall the Bing Bar

in case StartNow is not removed

Remove "Start Now" extension which puts Bing search into a new tab,

Tools > add-ons > Extensions or "Ctrl+Shift+A" > Extensions

then uninstall "StartNow" and restart Firefox. may be found in c:\program files (x86)\StartNow -- use the uninstaller in the StartNow folder.

Since you stated you want to have a new tab open with a different search engine than Bing, you would have to instal an extension as that is not part of Firefox and there is no configuration option for that. See

• New Tab Homepage :: Add-ons for Firefox
  https://addons.mozilla.org/en-US/firefox/addon/new-tab-homepage/

and be sure to read the author's comments, just in case you have one of those other extensions.

I only see disadvantages to opening a new tab with a search engine, so I don;t.

Thanks for the reply. I followed the instructions, but when I right click "keyword.URL" the word "reset" is greyed out and does not work. The other command options are bold. Any ideas? Do you know which Microsoft update changes it? I have the same OS on both computers, but one goes to a blank page while the other goes to the Bing page. It's a minor issue, but still frustrating. Thanks again! Jim.

I guess the order should be changed, so that the keyword.URL and fixing the homepage in Firefox are last. After fixing all all the Bing and StartNow things. You probably have to reboot system after making those control panel changes, and restart Firefox after making configuration changes (sometimes needed though most are effective immediately or in a new window).