Win 7 machines not visible to XP machines within same network

Hello,

I have a workgroup set up with about 10 computers: 6 running windows 7, and 4 running windows XP. This morning out of nowhere, the XP computers can't access the network (network is set up and hosted on Win 7 machine), and the Win 7 computers can't see the XP computers in the network.

4 things are happening that make this particularly weird:

1. from the Win 7 machines, I can ping the XP machines successfully, and from the XP machines I can ping the 7 machines successfully. They are both active on the network.

2. From the host computer (Win 7), I can see and access all of the XP computers, though the XP computers give me an error message when I try to even go so far as to find the Win 7 computers on the network.

3. From all the XP computers, I can see the other XP computers on the network, and from the Win 7 computers, I can see the other Win 7 computers.

and finally,

4. The Win 7 computer is hosting a database back end from which the front end on each of the computers (XP and 7) pulls the data. Both XP and 7 computers have no problem still pulling the data from the back end in the Shared Documents folder on the host computer, even though the XP computers can't see the network.

Any suggestions?

Are you in a Workgroup or HomeGroup? Did you check Advanced Sharing options?

I wonder why would all machines act up same time, maybe some security software common to all?

Check the state of these services:
Go to Start\Control Panel\ Administrative Tools\ Services.
- Computer Browser
- DHCP Client
- DNS Client
- Network Connections
- Network Location Awareness
- Remote Procedure Call (RPC)
- Server
- TCP/IP Netbios helper
- Workstation
-- Start one by one if above doesn't help
- SSDP Discovery
- UPnP Device Host
- IPSec

It's a workgroup. I have checked several of those settings, but some of those are a bit beyond my expertise. I could look at them, but I wouldn't know what I'm looking at. Can you be more specific?

Thanks

Try it only on one Win7 machine. Press Win+R and enter services.msc

Services window will open:
- Find each of the above services in the list and see if the services are Started. Note startup type as well (manual/automatic/automatic(delayed)/disabled)
- Start them if stopped. (Set to manual and start if currently disabled.)
- See if you will start seeing the others.
- If yes, restart and check again.
- If fails, then change manual ones to automatic. Start and check again.
- Restart and check if they work without intervention.

The only one that was not started was the UPnP device host. I started that, restarted, and still can't see any of the Windows XP computers.

Did the service stay started after the restart? If not, start the service again (but don't restart PC yet) and also check one of the XP machines, start it's services (don't restart, see if they will see each other). If they can't, nevermind that service and stop it.

I went to one of the XP machines, made sure everything was started, even went so far as to restart all of them. Should I restart all of the services mentioned above on the 7 machine? I misunderstood and thought that you meant to restart the computer.

Select 1 XP and 1 Win7, start the services, and see if they will discover each other. If not, don't bother anymore. I already think this is a slim chance, as services stopping on all machines same time is rather low.

Maybe a common security software on all of them?

Unfortunately, the computers still don't see each other. I'm unwilling to accept that they will never again see each other on the network, considering they saw each other just fine yesterday morning...However, from what I can see, nothing at all has changed in regards to the network settings, and nothing on the XP computers has changed.

Hey, see this thread Windows 7 clients can no longer access network drive
Looks familiar?

What security software do you use?