I've been using firefox for years since IE 10 doesn't work with Vista and haven't had too many problems other than versions higher than 42.0 being very slow to start (over ten seconds), so I try to use the lowest version I could. I used 38.0.1 with my problem which was with createspace on Amazon using their cover creator to create a cover for my self-published book. Two weeks went by and nobody could figure out why the cover creator program would hang on "update" with the circle in the middle. Nobody at Amazon, nobody at CreateSpace--in fact, they all reported they could access my cover just fine. So I cleared my cache and history, uninstalled Firefox back to 38.0.1 and even I tried version 52.0 and still, whenever I would launch the cover creator program within Amazon's Kindle Direct Publishing, I could not access my cover and the system would hang indefinitely on "updating" and "loading designs". So after two weeks, the thought came to me to try a different browser. Having limited choices for Vista SP-2, I downloaded Chrome 49.0.2623.112 and went back into the KDP cover creator and boom! No problems. I was able to update my cover with Chrome and get my book published because the stumbling block was Firefox. I tried IE 9.0 but of course, I got a notice by Amazon that said my browser was not supported and was stopped at the front door. The outcome was Chrome was able to do things that Firefox could not, and nobody was ever able to tell me why. Why did the cover creator program, neither a Java applet nor a flash program, would hang for hours on "loading designs" even after a fresh start and a clean cache. As a result, Firefox is off my system and I am still using Chrome with no problems. In fact, I want to keep it because it loads in like two seconds, shuts down in two seconds instead of ten, and browsing is much, much faster. The conclusion I have come to is that Chrome, although no longer supported, is superior to Firefox with the Vista operating system. I only have one plug-in and that is an ad blocker (ADP). Thoughts? I really wanted to stay with Firefox, but in this case, I had no choice because a book project I had worked on for 22 years was held up at the one-yard line by Firefox. The same problem was non-existent with Chrome. So I came to the conclusion that Chrome is better for Vista than Firefox (restatement of the same thing).