I plan to create very simple custom IP-STS for SharePoint foundation 2010 without ADFS server so anyone can integrate Windows Live ID to SharePoint foundation 2010 simply without ADFS, I can't use ADFS server because it could not install on Windows Web Server 2008 (Web Edition), also I found many article use LDAP provider but it does not exists in SharePoint Foundation too (it requires Sharepoint Server Edition). After too much searching I just found the following article and find all technique except one problem. 1) Creating Custom Claim Provider: blogs.technet.com/b/speschka/archive/2010/03/13/writing-a-custom-claims-provider-for-sharepoint-2010-part-1.aspx 2) Creating Custom STS Provider: http://blogs.msdn.com/b/chunliu/archive/2010/04/02/how-to-make-use-of-a-custom-ip-sts-with-sharepoint-2010-part-1.aspx Only one step remains: I got following error after enter username in STS site and redirect to localhost/_trust/default.aspx , ( I leave EncryptingCertificateName empty). Operation is not valid due to the current state of the object I expect to get access denied error instead of that error. 1.Is it possible anyway? 2.Can anyone help me where can I find working article to create custom IP-STS without ADFS server Any idea will help me Thanks