First off, here’s what worked for me:
Edit the file C:\WINDOWS\system32\drivers\etc\hosts (that’s the path in XP), and add a line matching the IP address of the server (computer that is hosting the multiuser access and files) with the Windows’ computer name of the server. For example, if the server’s name is my-serv and the IP address is 192.168.1.10, add the line:
192.168.1.10 my-serv
Now, to the background and other (hopefully useful) information.
I’ve been trying to setup Quickbooks for multiuser access, and it’s been a pain, but along the way, I’ve found some useful information and tools available from Intuit. Apparently, setting up multiuser access works fine often enough, but when it doesn’t, it’s a bit of a hunt to find out why.
Read the Guide
The first thing–which I wish I would have known about and done before any installation–is go to the Network/Multi-User Setups page on Intuit’s site, and read the Network Installation Guide for your version of Quickbooks. It gives useful information, such as that client computers should be installed as “One User” (at least in 2009 Premier), because apparently adding the line “Or this will be a client computer on a networked setup” was too much work. The Guide is very helpful.
But what if it doesn’t work? For me, I could open a file in Single User mode from the client, but to open it in multiuser mode from the client, I had to open the file on the server, switch to multiuser mode, and leave it open. Then I could open multiuser on the client (I think, in essence, it was defaulting to the “Alternative Setup”). Not optimal.
Download the Network Diagnostic Tool
Intuit has a Network Diagnostic Tool. It’s actually linked to on the above referenced page, but I missed it there and it’s not highlighted in the various searches I did. Download it and then click (on the download page) the “How to Use the Tool” tab. There’s not much in the way of “how do I fix this” information, or even explanations of what exactly some of the tests are checking for. But it’s a nice starting point.
What Worked for Me
The router at my office, for which I am responsible, is a Cisco DSL router, which apparently does weird things to DNS. I’ll admit that my being responsible for a router that I don’t understand is a WTF and obviously part of the problem, but is one of those unfortunate realities. Anyway, it occurred to me that maybe if I define the host name - IP address matching directly, that could help (some of the information in the console tab of the Network Diagnostic Tool got me thinking along these lines). In XP, that can be done by editing C:\WINDOWS\system32\drivers\etc\hosts (see the start of this entry). And it worked.