I use Firefox as my default browser. I was doing some regular browsing when all of a sudden it said 'This connection is untrusted'. It even did it to Google and Gmail so I knew something was up. IE worked fine. So I literally downloaded and ran 6 programs to remove adware and malware (Malwarebytes, adaware, spybot, superantispyware, etc.) and it still has the issue.

I got a notice that FIrefox was running slow before this and I refreshed it (without realizing that it would delete all of my addons). Now when I go to download ANY addon it says the download has failed. Also, when I search anything via the address window it pulls up the content but with NO CSS formatting. Not sure what is going on. I even uninstalled and installed an earlier version of firefox with no improvement.