Hi,
This issue may occur if the date and time on the computer varies too much from the valid date and time of the Secure Socket Layer (SSL) certificates that are used by the Windows Update Web site.
As you have already tried resetting the date and time, let’s try following the Method 4 from the KB article 929458.
http://support.microsoft.com/kb/929458
If that doesn’t work, then you may try resetting the windows update components.
http://support.microsoft.com/kb/971058
Let us know if that helps.
Regards,
Chethan Kumar.
Microsoft Answers Support Engineer. Visit our Microsoft Answers Feedback Forum and let us know what you think.