Q: When I ping the server using one of the clients it says the host is unreachable. Why?
A: 1) Make sure all machines are on the same local subnet and no routers in between.
2) Check the lmhosts file to make sure that you do not have an outdated file.
SYMPTOMS
when trying to set the IP address on a NIC, you may receive the following error message: "The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of adapter is hidden from the network and Dial-up Connections folder because it is not physically in the computer or is a legacy adapter that is not working. If the same address is assigned to both adapters and they become active, only one of them will use this address. This may result in incorrect system configuration. Do you want to enter a different IP address for this adapter in the list of IP addresses in the advanced dialog box? "
RESOLUTION
1. If you click Yes, you see the TCP/IP properties where you can change the IP address. Then assign the different IP.
2. If you click No, the IP address is assigned to the network adapter. To resolve this problem, uninstall the ghosted network adapter from the registry:
At command prompt, type set devmgr_show_nonpresent_devices=1, and then press ENTER. Type Start DEVMGMT.MSC, and then press ENTER. Click View, and then click Show Hidden Devices. Expand the Network Adapters tree and right-click the dimmed network adapter, and then click Uninstall.