For PCs in a Windows domain , the authenticating server is a domain controller ( a primary domain controller , or PDC , in Windows NT 4 - based domains ) .
For home PCs and PCs in a workgroup , the authenticating server is usually the PC itself .
For PCs in a Windows domain , the authenticating PC is a PC   ( a primary domain controller , or PDC , in Windows NT 4 - based domains ) .
For home PCs and PCs in a workgroup , the authenticating server is usually the PC itself .