To revert to Google as your preferred search engine, please do the following.

• In the location bar, type about:config and hit Enter.
• In the filter at the top, type: keyword.URL
• Double click it and remove whatever's in there and replace it with http://www.google.com/search?q=

The URL to add in "keyword.URL" becomes a link in this post, so right click it and choose "Copy Link Location" to copy it to the Windows clipboard. Then hit CTRL+V to paste it. Saves you having to type the whole thing.

To reset your home page, do the following.

• Go to the site you want to set as your homepage.
• Click the orange Firefox button and go to Options | Options | General
• Make sure it says "Show My Homepage" in the first dropdown menu.
• Click the button called "Use Current Pages" to set the homepage to the one you have on the screen.

After you complete the above steps, install this add-on to prevent another search engine from modifying your preferences: https://addons.mozilla.org/en-US/firefox/addon/browserprotect/

In addition, update Firefox to v4.0.1 by clicking Help | About Firefox | Check For Updates. A number of bugs have been fixed in the latest version along with some security issues.

After you complete the above steps, please visit the Plugins Check page and update where necessary.

By default Firefox opens a blank page when you open a new Tab, anything else and Firefox has been modified by something that was installed. You need to figure out what modified that action and get rid of it.

http://support.mozilla.com/en-US/kb/troubleshooting+extensions+and+themes

Once you get rid of the source of that modification you can install this extension to have your homepage open in a new Tab, instead of it being a blank page.
New Tab Homepage extension:
https://addons.mozilla.org/en-US/firefox/addon/777

Hi Zircal I tried this and no luck, a new tab still opens in facemoods search

Hi the Ed-mesister. How do I find out what caused the modification?