First of all turn off any firewalls for debugging. If the firewall is an issue, you'll have to configure it to allow access to "trusted zone" addresses. Note that some firewalls must be uninstalled to stop affecting your networking. For that you need to hold the Windows key and press R, then type CMD to open a command prompt. In the command prompt window that opens, you need to type the following commands:
PING each remote computer by IP address, and if successful, PING by name. Open a command prompt as described above and type.
PING <ip address>
PING <computer name>
<ip address> - is the x.x.x.x IP address
<computer name> - the computer name
A failure to PING is almost always a firewall configuration issue. Any failure to PING needs to be corrected before you go any farther.
After doing this you need to check all this things which are mentioned below.
Check your Services are Started on all PCs:
Network Location Awareness
Remote Procedure Call (RPC)
TCP/IP Netbios helper
You can check the services in Control Panel, Administrative Tools, Services.