You can change your webpage preferences back to Google from Yahoo. To change your homepage to Google you first must click on the three bars at the top right of your screen, it's the menu button. Then click on the "options" wheel. General settings will show up first and on that page under the "start-up" section it will ask you what you want as your homepage, and you can also set up whether you want your homepage to show when you open the browser or if you want a blank screen etc. Type in the Google URL and click out of your browser to save your changes.

To change your search preferences you first must go up to the search bar which is located right next to the browser bar. You will see a magnifying glass followed by "Search." Click on the magnifying glass, a menu will appear. Scroll down to "Change Search Settings," and click on it. You will be redirected to your Search settings. At the top of the settings page, it will ask you to choose what your search browser is using a drop-down menu. You can then proceed to choose Google as your primary search browser. Make sure to click out of your browser to save your changes.

I have done what you said, but my browser still comes back to Yahoo.

Do you mean when you click the Home button or Ctrl+n, Firefox just ignores your home page preference?

Or when you click the desktop icon, Firefox doesn't use your home page?

Or both?

Or the change works during your session but when you exit Firefox and start it up again, it has been reset? (For that, see: How to fix preferences that won't save)

Although the installer didn't complete, it may well have deposited malware on your system. Here's my suggested procedure for tracking down and cleaning up bad add-ons, hijackers, and ad injectors. I know it seems long, but it's really not that bad.

(1) Open the Windows Control Panel, Uninstall a Program (XP: Add/Remove Programs). After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. (XP may not have this column, try sorting by Last Used) This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it. Take out as much trash as possible here.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste
  firefox.exe "about:addons"

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. All extensions are optional; none come with Firefox.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

Success?