Sounds like a FAKE installer.

Download Firefox For All languages And Systems {web link}

You may have ad / mal-ware. Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

Followed all the instructions but when I download Firefox, it takes me to a page that can't be opened. The web site for that page is Raefughst.net.

I have run all the mal-ware removal programs I can find and while some were found and removed, the one above persists.

Hi JdSimpson, a couple follow-up questions:

(1) Is the mystery page set as your home page?

By default the home page in a new installation of Firefox is a built-in page named about:home. When you install Firefox, you can choose to import data from another browser, in which case, your home page may be the same as what you were using in that browser.

To check your home page, you can either:

• Launch a new window (Ctrl+n)
• Click the Home icon on the main toolbar to check that.

Does that re-open the problem page, or a different page?

If your home page needs to be updated, see either:

• How to set the home page
• Startup, home page, tabs, and download settings

(2) What Add-ons did Firefox discover on your system?

Sometimes extensions will hijack your browser in odd ways. You can view your list on the troubleshooting information page. Either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter/Return

Then scroll down to Extensions and just below that heading, select the table with your mouse and copy it (either Ctrl+c or right-click > Copy), then paste it into a reply (either Ctrl+v or right-click > Paste). It will look a bit messy, but we're used to it.