Running Windows 7 (64-bit). Two days ago, any time I started a new tab, I would get an error box similar to the one attached and the subjects line. About 3 to 4 times per tab open. No matter if I hit okay, or cancel, no difference. Everything worked as needed. Last night, firefox Quantum was forced installed, and now nothing works any longer. No internet connection, nothing. It's pretty much a dead piece of software. I have uninstalled it using various methods. One was to rename the folders in Program files to old and re-install. No go. Used the Control Panel - Programs and Features. No go. Followed about all instructions I could find, but the error does not go away. Reboots, safe mode, you name it. I even installed the previous copy, an no matter how often I change settings to not automatically install updates, that Quantum update will eventually force it's way in and be installed, no matter what. I think that pending update is what broke this, and now it completely non-recoverable. It's pretty much bricked at this point, and I have had to switch to Chrome for everything, while I used both depending on what I was doing in the past. The poor working and memory hogging of the past version forced me to use Chrome more and more, and I may have to give up on what once a good and decent product, as it apparently was not tested with Windows 7 as I see a series of similar issues, and no solutions. Everybody is provided with similar instructions, but I have yet to see a working solution.