First, please update to the latest version of Firefox that your computer will run. You can download it from http://ftp.mozilla.org/pub/firefox/releases/52.9.0esr/win32/
Please select the language you want, then download and install Firefox.
Windows Vista is no longer supported by Microsoft, so it is no longer receiving updates. That means it is not safe to continue using on the internet. You should upgrade to a supported version of Windows (7, 8 or 10), purchase a new computer, or install Linux if you are technically skilled enough to.
After installing the newer version of Firefox, what problems do you have?
Type in the address bar about:config and press Enter (promise to be careful, if asked)
The value should be true
If you had to change the value, then close and restart Firefox.
Cor-el has a good point - if you use an extension like
Adblock Plus, NoScript or Ghostery, then disable it on