Client not able to communicate with server

I have a windows server R2 hosting a couple a shares. the clients and the server are not in a domain environment yet. I can ping all the clients from the server, the clients can ping themselves from themselves. But the request gets timed out when they ping server. Also, they are not able to access the server shares anymore. Everything was working fine until about a week ago. I have checked the firewall rules(File and printer sharing( Echo request-ICMPv-4)) on both sides (client and server), and everything seems fine. Network discovery is turned on, on both client and server. I read on a “computer browser” service that can affect it if not running. Checked and set it to automatic start on the server.
These have however not changed the situation. Kindly help. Thanks.