Hey sgrodner,

Trust me, this isn't a Firefox issue. Are you the only person that uses the computer? It sounds like, for whatever reason, your homepage has been changed. Some sites will try to do this and this can also be caused by malicious software. The first thing I would try is to change your homepage. You can find steps on how to do this in the article How to set the home page. I would suggest that you first try restoring the homepage options to default. If that works, you can try setting a custom homepage. If your default search engine has been changed too, you should should read the Search bar - add, change and manage search engines on Firefox article as well.

If that doesn't fix the issue, you may have some sort of malicious software on your computer. A good antivirus scan should clean that up.

Hopefully this helps!

Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
• http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked