Question : Machine not pingable form network.

One of the machines on our local network segment is not pingable - Request timed out - nor is it reachable via UNC or the managment console.  All users on this machine - we have had several logged in - can ping and unc from the machine but none of the other machines can reach it.
It is acting like the firewall is on - but the XP firewall is off and the option to turn it on is greyed out.
Besides having been restarted - and even powered off for a weekend - several times; Service pack 3 has been installed - no go;

Did a search on Experts Exchange and came up with the following possible fix:
For Windows XP Home Edition

1. Click Start, Run and type Regedit.exe
2. Navigate to the following locations:

HKEY_LOCAL_MACHINE \ SOFTWARE \ Policies \ Microsoft \ WindowsFirewall

-and-

HKEY_CURRENT_USER \ SOFTWARE \ Policies \ Microsoft \ WindowsFirewall

3. Backup and then delete the WindowsFirewall key.
4. Close Regedit.exe and restart Windows.

For Windows XP Professional

* Click Start, Run and type Gpedit.msc
* Navigate to the following branch:

Computer Configuration
=> Administrative Templates
==> System
===> Network
===> Network Connections
====> Windows Firewall
=====> Standard Profile

* Set the following options to Not Configured (defaults)

Windows Firewall: Protect all network connections
Windows Firewall: Do not allow exceptions
Windows Firewall: Define program exceptions
Windows Firewall: Allow local program exceptions
Windows Firewall: Allow remote administration exception
Windows Firewall: Allow file and printer sharing exception
Windows Firewall: Allow ICMP exceptions
Windows Firewall: Allow Remote Desktop exception
Windows Firewall: Allow UPnP framework exception
Windows Firewall: Prohibit notifications
Windows Firewall: Allow logging
Windows Firewall: Prohibit unicast response to multicast or broadcast requests
Windows Firewall: Define port exceptions
Windows Firewall: Allow local port exceptions

* Exit the Group Policy editor.

After both of these options - machine was restarted, but it is still not reachable.  However, the Windows firewall options are now available - we have made sure they are turned off.

Any ideas - we're all out!

Answer : Machine not pingable form network.

Sounds like a stack issue. If not firewall, antivirus or the likeis enabled and you could ping it with a modified stack briefly, it sounds like it needs repiared. Try this.

http://support.microsoft.com/kb/299357