Why can't I ping 192.168.0.3 while NET USE is fine?
Sophia Terry 
I shared a folder c:\users\ on a Windows 7 desktop that is connected to a cable modem/wireless router. I have an XP desktop cabled to the same modem/router. It's an ARRIS or Motorola Surfboard SBG6580 that I just bought used. Both (desktop) boxes get internet fine.
In order to reach the W7 box files, on an XP prompt I goNET USE \\\192.168.0.3\users
andSUBST Q: "\\\192.168.0.3\users\Bob"
Those work flawlessly. Since I gave full access when I shared the Win7 folder, I can read and write to everything by using Q: on the XP box.
But since replacing the modem (same brand/model as before), ping doesn't work anymore. The IPs have not changed. (By the way it could be a coincidence that this began when I swapped out the modem, because I didn't try the ping until a week later.) Anyway, now,ping 192.168.0.3 -n 1 -w 1000gets 100% loss each and every time.
I went through every single screen after browsing/logging into the modem at and don't see that I'm blocking anything anywhere. It has a setting for IPv4 Firewall Protection which I changed from Low to Off. (When it was Low, I had Port Scan Detection checked.) Anyway, that screen says "No Ports Restricted."
Also tracert 192.168.0.3 -w 200
times out every time, in case that's meaningful. arp -a shows nothing about address 192.168.0.3. (both run on the XP box)
I've turned off the 3rd party XP software firewall (which had whitelisted ping anyway). Restarted both boxes and the modem.
Small note, NET USE reports status "Disconnected" sometimes even though I know the connection is good. If I go DIR Q: and immediately go NET USE again, this time it reports OK. I assume that's just a peculiarity with NET USE.
EDIT: Thanks for the ICMP suggestion but 192.168.0.1 pings okay as does 192.168.0.2 as does google.com. It's not that all PINGs fail; just this one.
31 Answer
The firewall on 192.168.0.3 was mistakenly set to block incoming ICMP packets.
