If you grabbed the small "stub" installer from the main page, try again using the "full" installer on the "all versions" page here (scroll down to your language):

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

Does that one work on Windows 8.1?

Jscher you rock! That totally worked.

Thank you for saving me from being condemned to using IE!

That worked. Thank you very much for the help.

I have a variant of this problem. Since upgrading to Windows 8.1, I have been unable to install Firefox for multiple users on this laptop. Firefox installs only for the Administrator (me) installing it, and does not appear on any other account. If I try to install the program from one of the other accounts, it does not install.

Hi djaroslaw, I moved my reply over to your new thread here: https://support.mozilla.org/questions/988334#answer-539651