I need to install a root certificate so that the certificate my email and web-dav servers use can be authenticated. I download the root certificate and put in the "Trusted Root Certification Authorities" store. I can then use certmgr.msc to look at the store and the certificate is indeed shown in it. It will work for a while after the install, but eventually I will start getting the message:"The server you are connecting to is using a security certificate that cannot be verified. A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider."Then if I use certmgr.msc to look at the trusted root certification authorities store, the certificate I previously installed is no longer there. I can re-install it, but it always disappears eventually.I'm running Windows Vista with service pack 1 and have had this problem on multiple computers with this setup. They are not members of a domain.The certicate is valid from 2003 to 2013 so it is not an issue with things expiring. Most recently I installed the certificate yesterday and it worked yesterday, but has disappeared again today...Thanks,John Wilkinson

Hi John, after checking the issue, it seems this is a general Outlook related issue. As this forum focuses on Windows Vista specific issues, this inquiry would best be posted to Outlook newsgroup: http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.outlook.general The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the newsgroups regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.

This is an issue with Microsoft Vista's storage of root certificates in the certificate store. Certificates are used by many programs, not just Outlook. Specifically any website that uses SSL needs to authenticate the certificate used by the website against the root certificates in the store which is maintained by Vista as far as I know, not Outlook.This issue did not occur on Windows XP so I would say it is definitely a Windows Vista issue.I will try the newsgroup that you suggest, but this is no way an issue with Outlook, unless Outlook is somehow deleting the root certificate from my store.Another user of my WebDAV server who is running Vista is having the same exact issue as me, they do not use Outlook for their email, they use Thunderbird. As far as I know the rest of the users are still on XP and not having this problem.

Hi, Did you get it to work ? I have the same problem. Thanks Hugues

I have the exact same problem. can someone please help? Thanks, Anagha