If this is searching from the location bar, you can change a hidden preference to restore it to Google.

1. Type about:config into the location bar and press enter
2. Accept the warning message that appears, you will be taken to a list of preferences
3. Locate the preference keyword.URL, right-click on it and choose Reset

If it is searching from the search bar, see the Search bar - add, change and manage search engines on Firefox article for details of how to change search engines.

Your above posted system details show outdated plugin(s) with known security and stability risks that you should update.

1. Shockwave Flash 10.0 r45
2. Java Plug-in 1.4.2_03 for Netscape Navigator (DLL Helper)

Update the Flash plugin to the latest version.

• http://www.adobe.com/software/flash/about/

Update the Java plugin to the latest version.

• http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)

Your user agent shows a SearchToolbar/1.2 addition, so you may have an extension that is causing your problem.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
• Removing the Search Helper Extension and Bing Bar