Not able to ping computer

From the command prompt (assuming windows)

ipconfig /all

Assuming that your subnet mask is 255.255.255.0 then the first 3 octets should match your other PCs. If this is not the case and you're using DHDP do;

ipconfig /renew

Also check that you have a connection to your switch/router.

Have you ensured the firewall on the computer that you are unable to ping is set to allow echo requests?

Try this....

1.From the Start menu, select either Control Panel, or Settings and then Control Panel. Click or double-click Network Connections to open the Network Connections window.

2.In the Network Connections window, right-click the icon for your primary Internet connection and select Properties. For example, if you connect using an Ethernet cable, right-click Local Area Connection; if you connect using VPN or dial-up, right-click the Virtual Private Network or Dial-up Connection.

3.On the Advanced tab, under "Windows Firewall", click Settings... .

4.The Windows Firewall panel will open. On the Advanced tab, under "ICMP", click Settings... .

5.The ICMP Settings window will open. Check Allow incoming echo request.

6.Click OK three times.