Lotus Foundations and Windows 7

Joining a Windows 7 workstation to a Lotus Foundations server configured as a domain controller is not currently supported. If a Windows 7 workstation is configured in workgroup mode, it can use  the file sharing services on a Lotus Foundations server.

Attempts to join a Lotus Foundations domain controller from a Windows 7 workstation will result in the following error:[
The specified domain either does not exist or could not be contacted.

Providing compatibility between Windows 7 workstations and Lotus Foundations based domain controllers is a high priority for IBM and a fix is on our road map.

The information above is from TN1409287