the network path was not found joining domain

Hi.
one of my clients can't join to the domain.
I changed my modem-router 1 month ago.but i don't know how to change modem router DHCP server.
this may help to answer.

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\Sepidam>nslookup ad.chigs.m
Server: google-public-dns-a.google.com
Address: 8.8.8.8

Non-authoritative answer:
Name: ad.chigs.m.royanco.com
Address: 54.208.247.222


C:\Users\Sepidam>ipconfig/all

Windows IP Configuration

Host Name . . . . . . . . . . . . : Mohammadi
Primary Dns Suffix . . . . . . . : royanco.com
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : royanco.com

Ethernet adapter Local Area Connection* 18:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Anchorfree HSS VPN Adapter #2
Physical Address. . . . . . . . . : 00-FF-DC-BE-BF-F0
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection* 16:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Anchorfree HSS VPN Adapter
Physical Address. . . . . . . . . : 00-FF-75-6E-C3-61
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::79f5:15e8:d840:424c%15(Preferred)
IPv4 Address. . . . . . . . . . . : 10.254.168.17(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.248.0
Lease Obtained. . . . . . . . . . : الأحد, سبتمبر 21, 2014 10:05:28 ق.ظ
Lease Expires . . . . . . . . . . : الإثنين, سبتمبر 21, 2015 10:05:28 ق.ظ
Default Gateway . . . . . . . . . :
DHCP Server . . . . . . . . . . . : 10.254.175.254
DHCPv6 IAID . . . . . . . . . . . : 620822389
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1B-0F-8C-20-00-1A-4D-8E-DD-F8

DNS Servers . . . . . . . . . . . : 8.8.8.8
NetBIOS over Tcpip. . . . . . . . : Disabled

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : 192.168.1.20
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : 00-1A-4D-8E-DD-F8
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::ed00:4f81:dfa5:cc23%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.21(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : الأحد, سبتمبر 21, 2014 10:04:36 ق.ظ
Lease Expires . . . . . . . . . . : الإثنين, سبتمبر 22, 2014 10:45:31 ق.ظ
Default Gateway . . . . . . . . . : fe80::6889:3fff:fe47:b964%11
192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 234887757
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1B-0F-8C-20-00-1A-4D-8E-DD-F8

DNS Servers . . . . . . . . . . . : 85.15.1.12
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:9d38:90d7:300e:3b56:f501:57ee(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::300e:3b56:f501:57ee%17(Preferred)
Default Gateway . . . . . . . . . : ::
NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.{756EC361-6229-4D5C-9D0E-EA6BF0BF93E8}:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #7
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::5efe:10.254.168.17%18(Preferred)
Default Gateway . . . . . . . . . :
DNS Servers . . . . . . . . . . . : 8.8.8.8
NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.192.168.1.20:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : 192.168.1.20
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #9
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Welcome to the forum.

In an active directory domain the client always looks for the domain controller using DNS, even when it is on the same subnet. All clients must be set to use the domain DNS server. Typically the client would obtain this information from the DHCP server, usually running on a server in the network. DHCP on the Internet router would then be turned off.

I disabled DHCP on server.
But still i can't join my clients to domain

Elham said:

I disabled DHCP on server.
But still i can't join my clients to domain

That is not what I suggested. Typically DHCP functions would be provided by a server in the domain, not the Internet router although it could be done that way. DHCP would then provide the address of the domain DNS server. This is critical. Without a domain DNS server the client will not be able to find a domain controller and will not be able to join the domain. The ipconfig data shows that the client is using an Internet DNS server which cannot be used for this purpose.