To have the users automatically login to Portal using their windows credentials, you need to implement Windows Authentication using Kerberos using SPNego Wizard...
This will enable the users to login to Portal automatically as soon they open the Login Page.
Check this help on how to implement - http://scn.sap.com/people/wai-hon.lam/blog/2006/04/20/windows-integrated-authentication-via-kerberos-on-an-ldap-data-source
Sandip
is there other way to configure SSO that isn´t kerberus?
No as far I know..If you want to do SSO based on windows credentials, you need to use Kerberos..
Is there any restriction that you dnt want to use it?
There are other solutions available, like siteminder or openAM. But I'm not sure if these fit your requirement, as you still will have to log on to these solutions
How to configure Kerberos SSO is well documented at SAP Help and there are also documents and blogs published here at SCN. Have you search and implemented the steps outlined in these documents? If so, what is the actual error you get?
