So, my Firefox browser crashes when a certain among of RAM is used up. This began after I updated to 38.0, although not immeadiately after. Whenever 77% of RAM was used up firefox would crash. By following steps in guides, such as disabling add-ons & hardware acceleration I slowed the rate that the RAM would be filled. Then by disabling somethings in msconfig I increased this percentage to 83%. Doing these allows me to browse for longer without crashing, but didn't do anything to actually stop it. I try to "file -> exit" Firefox before this happens, but if a lot of RAM is already being used it will crash whilst exiting. In short, I think Firefox can't handle it's RAM, which just steadily increases until it crashes. This began a couple of weeks after the 38.0 update and I am now using 38.0.5. I think I may have tweaked a setting to cause this, but can't find where.