Question : Security certificate error in Outlook 2007 (error 8)

I am getting the following error:

There is a problem with your security certificate. The certificate is not from a trusted certifying authority. Otlook is unable to connect to the proxy server mail.ourdomain.co.uk (error code 8).

It is from a Windows 7 pro laptop where the user logs on from a remote site and is trying to connect Outlook 2007 to the Exchange server.

The exchange server is on a SBS 2003 server.
The connection is by using 'Outlook Anywhere' over HTTP.

ALL the XP laptops which have Outlook 2003 or 2007 connect with no problems.

I have read that I have to issue a certificate from the server and install on the Win7 laptop.
Could someone tell me how I do this and how if at all it will affect the other laptop users who are running XP. At the moment I have 1 irate user who cannot get their mail, I don't want a whole gang of them phonig me!

Thanks for your time.

Answer : Security certificate error in Outlook 2007 (error 8)

Probably eaisiest to do this by using the Webmail function https://servername/exchange to get to the certificate using IE and install it so any program on the pc can use it...