Networked PC unavailable until accessed via Explorer

I have a home network of PCs using Windows XP + Vista 32/64.
I don't use a DHCP - they all have static IPs.

I'm posting this topic as I have occasionally been unable to access various computers on the network from DOpus in either of two ways:

[1] I open the "Network" namespace and Vista scans for connected PCs and a particular PC is not visible.

[2] I access the PC directly using its UNC (eg \NetPC) and DOpus fails to connect

Now, I have had this problem about 4 times so far at various times and to get DOpus to successfully access the networked PC I must do the following:

[1] Open Windows Explorer and type in the UNC, eg \NetPC
[2] Close DOpus
[3] Re-open DOpus

Now DOpus will access the PC in question 100% fine.

One interesting thing here is that DOpus will not display the PC in the Network namespace yet as soon as I open this namespace in Windows Explorer, the PC is shown. Other PCs are visible in the Namespace in DOpus, just not this particular one (and it is not always the same PC!).

I've posted this simply as a pointer to something that I'm looking into and when I have time (ie, I don't need to access whatever PC it is quickly) I'll diagnose it further.

Actually, I get this quite a lot - DOpus seems slower to pick up UNC than explorer and has trouble finding PCs on a network until they are accessed via Windows, (Explorer, etc).

However, DOpus will always access first time when I use the IP, eg. \ Assuming there isn't a firewall problem or something.

Since I use set the router to use Static DHCP, (same IP always assigned to same adapter), I set up some buttons to:

Go \

And name the button 'NetPC1' or whatever.

And considering that you have static IPs, this should be faster than having DOpus go look at a hosts file or other UNC/IP lookup table.

A good tool when diagnosing LANs is SoftPerfect's NetScan

If it can't see it, then DOpus can't. And if it can, then DOpus will.
Plus it will show if a PC has shares, then you just doubleclick on it and a lister will open.


I use DOpus over our home network (2PCs and 3 laptops all running XP Pro) and provided all all of the drives shared on the network are mapped, I have no problems. DOpus is quick and reliable with any machine turned on.

Right now, I have three PCs in my home office, and often more when I'm working on a customer's PC. I find that it helps to temporarily map a a network drive to the each of the other PCs and save the credentials (so the drive maps automatically upon reboot). After you do this, Opus should be able to read the mapped drive no problem. Then, you can then unmap the drive and UNC access should work just fine, without you having to keep drives mapped all the time.

If you are using a mix of Windows Vista and Windows XP PCs, download and install the Layer Topology Discovery (LLTD) Responder (KB922120)[/url] on your Windows XP machines. It will help the Vista ones see and update their network topology diagrams.