my server is in win server 2003 in a domain and clients are in workgroup they are accessing each other successfully now i have change the ip of my server & clients from 192.168.0.x to 192.168.4.x but client are unable to access the server it gives request time out error but the server is pinging the clients now how i'll connect the client after changing the ip series

Did you change the host records in DNS to reflect the IP change? If not, you'll definitely not be able to connect to it using the hostname of the server to connect. A quick way to check if it's the DNS...........can you ping by IP but not by hostname? If yes, then it's the DNS.

You changed the server to a different subnet, so as far as the clients are aware the server is gone. You need to change ip on clients as well (if you use static ip you have to do it manually but if you're using DHCP just change the scope). The first three groups of numbers in the ip adress (192.168.4) is the subnet address and the last group is the host address. Hosts means clients, printers, servers etc, and in order to see each other they all need to be on the same subnet. Unless you use LAN routing which is a different story.

You need both the DNS change and a routing change. Like said above you can not talk accross subnets with out setting up a static route or router to connect the different networks. You can simply do a Route Add 192.168.4.0 mask 255.255.255.0 192.168.0.1 This is assuming your router is 192.168.0.1 and you are using /24 subnets. You will also need to add the HOST (A) record as suggest above or you will not be able to use FQDN in your mappings. Its best not to mess with your server IP unless you really know what your doing.