Security software is a possible issue. If you click to expand the "Technical Details" of the error page, does it show this code:

• sec_error_untrusted_issuer

A common problem recently is Firefox not being set up to work with your security software. Some security suites include a filtering feature. In order to filter secure connections (HTTPS URLs), the security software presents a fake certificate to Firefox so it can intercept and stand in the middle of the secure connection. To have Firefox trust these certificates, you may need to do something such as import a root certificate, or click something in your security software's settings.

Of course, the problem also could be caused by spyware.

If you have added Exceptions, please check the "Issued by" section on one or two of the exceptions you've made to learn more about the source of this issue.

orange Firefox button (or Tools menu) > Options > Advanced > Certificates mini-tab > "View Certificates" button > Servers tab

Click a certificate and use the View button. The kind of issuer you might find is:

• Name associated with your security software, such as ESET, BitDefender, etc.
• Sendori (indicates unwanted software from Sendori)
• FiddlerRoot (indicates unwanted software named similarly to BrowserSafeguard, BrowserSafe, SafeGuard)
• Something else

If you have not added Exceptions, you can click the Add Exception button in the error page, then in the dialog click View Certificate or Get Certificate to see the Issued by section. You do not need to finish adding an exception.

What do you see?

I found a program called BrowserSafeguard with Rocket Tab by BrowserSafeguard was somehow on there I uninstalled and things are better, I think, somehow I keep getting ads that pop up and seem to take over, wish I could find where they're coming from

You found BrowserSafeguard in the Windows Control Panel? Good catch. Anything else unexpected there? Sometimes clicking the "Installed on" column heading helps figure out what was bundled with what.

Within Firefox, you may have an unwanted extension that is injecting inappropriate ads into sites. Try this:

Disable ALL nonessential or unrecognized extensions on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions. Then, if in doubt, disable.

Usually a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Does that change the ads you see?

A note about the Remove button: if there isn't one, usually that indicates that the extension was installed externally to Firefox, and hopefully there is a way to uninstall it through the Windows Control Panel.