I bought a new computer and every time I try to get to websites that I have used before I keep getting a "site is not secure" message. I have uninstalled and reinstalled Firefox several times. Still can't access sites! I teach online and the school websites are the ones I can't get on. I have Comcast internet and Firefox worked fine on my old computer. I have a Windows 10 OS but did on my former computer. I have been to Geek Squad and Firefox worked fine in Best Buy. I contacted Xfinity support and spent an hour on the phone and they couldn't figure it out. Our school IT coordinator can't find the problem. I have tried all of the troubleshooting on Mozzilla and can't find the answer. And now my profile info is missing and I can't even open Firefox at all. I have tried attaching a screen shot of the messages but it doesn't seem to upload. I give up! Please help!