Just reinstalled a clean Windows. First download: Firefox of course :P Trying to download Firefox in Spanish or English gave issues with Internet Explorer. Steps: -Google "firefox descarga" (or) download -Click on download firefox -See filename "Firefox Setup Stub 31_0_exe" -Click on Open (fails of course) -Click on Save (fails) -Click on Save As (fails), click on retry, now it downloads correctly. -Rename "Firefox Setup Stub 31_0_exe" to "Firefox Setup Stub 31_0.exe" in order to open it. Why is this happening? Please try and fix it asap, users with less skills will get extremely confused. Glad to help :)