I got a mac so it is different. Never had this issue.
Try this last one before you think about going to the professionals.
Before doing this, go to my last post and click enable all.
Start Menu> Type "msconfig" > Click on "msconfig" > Click on startup > Enable all > Click apply
The certificate is not trusted because the issuer certificate is unknown
(site name) uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. (Error code: sec_error_unknown_issuer)
The file cert8.db in your profile folder may have become corrupted. Delete this file while Firefox is closed.
- Open your profile folder:
Click the menu button
, click help
and select Troubleshooting Information. The Troubleshooting Information tab will open.
- Under the Application Basics section, click on Show in Finder. A window with your profile folder will open.
Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
- Click the menu button
and then click Quit
.
- Click on the file named cert8.db.
- Press command+Delete.
- Restart Firefox.
cert8.db will be recreated when you restart Firefox. This is normal.