So its time to ditch Firefox and find a better solution for browsing. Most people usually go for Google Chrome, but now even Chrome has stopped all support for Windows Vista users. You could always download an earlier version of Chrome and it will still work. However, it will be quite buggy and will no doubt become unstable and annoying to use at times.
As a Vista user myself, the browser I have moved on to is Pale Moon. It's very similar to Firefox but much faster and more stable to use. It's not perfect though. One area that it struggles with is captcha's. It can't click the "I'm not a robot button". This can be an inconvenience, but after a while you just get used to it. For important things that need me to solve the captcha, like submitting my website / blog posts to Google Webmaster Tools for indexing, I use Firefox.
So if you do download and use Pale Moon, make sure you keep Firefox installed on your computer and fire it up if you need to complete a captcha. Other than this issue Pale Moon has been a good browser so far to use with Vista 32bit and 64bit. I have Vista 64bit OS installed and I'm using Pale Moon version 27.9.4 (32-bit) and it works well. If you want to use that you can find that version here: https://ia601306.us.archive.org/zipview.php?zip=/25/items/Pale_Moon_Archive_2015_08/Pale_Moon_Archive_2015_08.zip.
Or you can download the latest release here: https://www.palemoon.org/download.shtml
