At first I can access everything. After a while a generic host problem window pops out and says encounterd a problem. After that I can't share or access any files in network. Then from services I manually started the network connection. Still can't share. After that when repairng the network connections, it says "can't register with dns".

I use avg 8.5 free and it shows resident shield detected.


Need desperete help...

Is this a home network or company network?

Take a look at the Network Diagnostics (https://www.askmehelpdesk.com/networking/networking-diagnostics-helpful-hints-282387.html) tips post at the top. Check your network cable connections and report back your IP configuration information.

well it's a normal home network which has 20 computers connected using 24 port hub.

the ip configuration is

Windows IP Configuration

Host Name.. . : SERVER
Primary Dns Suffix.. . :
Node Type.. . : Unknown
IP Routing Enabled.. . : No
WINS Proxy Enabled.. . : No

Ethernet adapter Local Area Connection 3:

Media State.. . : Media disconnected
Description.. . : Realtek RTL8139/810x Family Fast Eth
ernet NIC #3
Physical Address.. . : 00-E0-4C-12-5A-32

PPP adapter utl 2:

Connection-specific DNS Suffix . :
Description.. . : WAN (PPP/SLIP) Interface
Physical Address.. . : 00-53-45-00-00-00
Dhcp Enabled.. . : No
IP Address.. . : 172.18.44.64
Subnet Mask.. . : 255.255.255.255
Default Gateway.. . : 172.18.44.64
DNS Servers.. . : 115.187.17.50

C:\Documents and Settings\Server>ipconfig /all

Windows IP Configuration

Host Name.. . : SERVER
Primary Dns Suffix.. . :
Node Type.. . : Unknown
IP Routing Enabled.. . : No
WINS Proxy Enabled.. . : No

Ethernet adapter Local Area Connection 3:

Connection-specific DNS Suffix . :
Description.. . : Realtek RTL8139/810x Family Fast Eth
ernet NIC #3
Physical Address.. . : 00-E0-4C-12-5A-32
Dhcp Enabled.. . : No
IP Address.. . : 192.168.1.29
Subnet Mask.. . : 255.255.255.0
Default Gateway.. . : 192.168.1.1
DNS Servers.. . : 192.168.1.1

PPP adapter utl 2:

Connection-specific DNS Suffix . :
Description.. . : WAN (PPP/SLIP) Interface
Physical Address.. . : 00-53-45-00-00-00
Dhcp Enabled.. . : No
IP Address.. . : 172.18.44.64
Subnet Mask.. . : 255.255.255.255
Default Gateway.. . : 172.18.44.64
DNS Servers.. . : 115.187.17.50

OK. What operating system is the SERVER running? I would assume that your DHCP Scope is something like 192.168.1.50 - 100. The point is that the .29 address that the server is using is NOT within the range of the DHCP Scope?
Also, what type of device is 192.168.1.1? Is it a cable/DSL router? Does it actually have DNS capabilities? I would assume that the TCP/IP configuration of your SERVER includes the automatic registration in DNS? If this is so and your router does not have dynamic DNS capabilities, then it can not register.

If the host SERVER is actually running a server OS like Windows Server or Small Business server, then you should also install DNS on it and change your router to point to it for DNS. You have to enable forwarding on it so that it would forward all non-domain requests on to your ISP's DNS via your router. Without a valid DNS server on your local network, the only form of name resolution you will have for your home network is NetBIOS via Windows Browsing.

Lastly, if your SERVER does not have a Windows Server OS but instead has something like Vista or XP Pro, then that is your trouble. It will allow only up to 10 share connections at a time.