Error:  One or more intermediate certificates in the certificate chain are missing. This is because Windows does not have enough information to verify this certificate.

When upgrading a Server 2003 IIS 6 web site to 2008 IIS7 the certificate exported from IIS6  you may have issues causing windows to give you the ‘Windows does not have enough information to verify this certificate’ error.

This is because one or more intermediate certificates in the certificate chain are missing. To resolve this issue, make sure that all of intermediate certificates are installed. For more information: http://support.microsoft.com/kb/954755  

Resolution:  This involves installing the intermediate certificates into the IIS servers, please view the following:

Download the Intermediate certificates applicable to your product:
Note: You MUST install correct thawte Intermediate CA file on your server for your SSL certificate to work and be fully supported in all web browsers.

SSL123:
Thawte DV SSL
Thawte Primary Root CA 2020

SSL Web Server / SSL Web Server Wildcard:
Thawte SSL CA 
Thawte Primary Root CA 2020

SGC:
Thawte SGC Intermediates (certificate requested before 10.10.2010)
Thawte SGC CA – G2 and VeriSign Class 3 Public Primary Certification Authority – G5 (certificate requested after 10.10.2010)

Thawte Extended Validation:
Thawte Extended Validation SSL CA
Thawte Primary Root CA 2020