Suddenly my Win 7 machine is unable to ping by name an XP machine on the LAN, but by IP number it works.
What could be the problem?
The Win 7 machine is connected to the router wirelessly, but the XP machine is connected by cable to the router.
I have solved the problem and I offer the following in case it might help people with the same issue:
First I went into the WINS tab inside the TP/TCP settings of the LAN connection and enabled NetBIOS.
Then I did
I then changed the NetBIOS setting back to default in the WINS tab.
The problem has gone away now, but I don't know exactly what had fixed it.
EDIT: Another thing that can fix this issue is making sure both machines are on the same Workgroup.