Firefox, if downloaded from the official Mozilla website, does not ship with anything other than the browser.

• https://www.mozilla.org/en-US/firefox/new/
• https://www.mozilla.org/en-US/firefox/all/

<strike>Unfortunately, it seems your wife's computer is infected with a virus, and a pretty difficult one at that. It seems to change a lot of settings and system files. You would need to go to Windows Safe Mode to repair these files, in addition to running antimalware scanners.

I cannot find a simple guide to follow so I recommend posting on a forum specializing in malware removal to receive step by step instructions personalized to what is found on your infected computer:

• Bleeping Computer - http://www.bleepingcomputer.com/forums
• Spyware Warrior Forums - http://www.spywarewarrior.com/index.php
• SWI Forums - http://www.spywareinfoforum.com/</strike>

Edit: My mistake, it is not a virus, see - http://answers.microsoft.com/en-us/windows/forum/windows_xp-security/how-to-remove-ngnix-virus-from-windows-xp-pro/6b95b9ad-b64e-43f7-bc02-2a335b57b93e

nginx is server software that can run on servers on the internet, so you can see such a message when you go to a web page using a link that doesn't have a page at that address.

Clear the cache and remove cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

You can check the home page setting:

• Tools > Options > General > Startup: Home page

Firefox supports multiple home pages separated by '|' (pipe) symbols.

• https://support.mozilla.org/kb/How+to+set+the+home+page