SharePoint 2010

Symptom: do users complain that they need to login over and over when opening and saving word documents on your SharePoint ( MOSS2007 /SP2010 ) portal?

Then you probably have used a FQDN for your portal url.

The fix is quite easy if you have Vista or Windows 7 clients:

http://support.microsoft.com/?id=943280

Short version:

Add a reg key to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters"

with the name: AuthForwardServerList (MULTI_STRING) and add your portal urls as values:

(Crosspost of: http://stefvanhooijdonk.com/2010/06/23/login-troubles-with-word-and-sharepoint )