Setting the Security Mode on the Domain Controller
You must enable Domain\Users to use Windows Authentication mode on any Commerce Server site. You must also enable Domain\Users for the Supplier Solution Site on which you want to use Basic Authentication (not Integrated Authentication).
To set the security mode on the domain controller
Click Start, point to Programs, point to Administrative Tools, and then click Domain Controller Security Policy.
In the Security Settings tab, click Local Policies, click User Rights Assignment, and then click Log on Locally.
In the Security dialog box, add Domain\Users to this policy, and then click OK.