If you use Windows NT 4.0 you need ADSI. You can download from microsoft.com. If you use Windows 2000 you need Active Directory installed. I had the same problem and solved it with ADSI. Still have some probs with line 1264...
Microsoft VBScript runtime (0x800A01B6)
Object doesn't support this property or method: 'strNTUserInfo.Groups'
/inc_functions.asp, line 1264