I am not able to open gmail and some other sites

Question

Last day my system got hanged so I restarted and recovered windows to the the date of 1 day before. Now I am not able to open gmail, orkut and some other sites. When I try to open these sites I receive this message:

This Connection is Untrusted www.google.com uses an invalid security certificate. The certificate is not trusted because it is self-signed. The certificate is only valid for 78-159-121-94.local (Error code: sec_error_untrusted_issuer)

Answer 1

The message...

www.google.com uses an invalid security certificate. The certificate is not trusted because it is self-signed. The certificate is only valid for 78-159-121-94.local

...appears to indicate that, instead of connecting to www.google.com, your computer actually connects somewhere else. More precisely, to 78.159.121.94, a computer in Germany. That computer also has a web server running, which is kinda suspicious... (although it has nothing resembling a fake Gmail website or anything such.)

• Check your DNS server settings.
• Check %SystemRoot%\System32\Drivers\etc\hosts.
• Check if the same is happening with other browsers (Opera, Internet Explorer).
• Test from a LiveCD.

Answer 2

You have to set the correct time to use https protocol for example.
You'll experience this until you set it back to normal.

(Happened to a friend of mine also since he was "lazy" to set it up.. guess he have some trouble with his mainboard. Besides that, correct time is the key.)

Answer 3

You need to set the time or more likely the date of your computer operating system. Click on the time in the system tray and you'll probably find the date is in the past.