hello, please double-check that your system is set to the right date, time & timezone: time.is

I have done that already, that was the first thing I did. I should note I'm able to go to all the other sites I regularly go to..Yahoo.com is the only issue

ocsp is a certificate verification protocol that is time-sensitive to the matter of a few hours (IE doesn't support it by default, so it's no surprise when you don't get an error there)... so please, even if you have already checked the time, please double-check your system clock again in that order: timezone, date, time

time.is

We have seen reports that the time as set via an internet based time service was so much out of sync that an error occurs, so if that is the case with you this service or try to switch to another time service.

You can check the connection settings.

• Tools > Options > Advanced > Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can

Boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/