"account currently disabled" when accessing share, even before logging in

When I try to access a share folder, say \\share-folder, I get the following error message:

logon failure: account currently disabled

This seems strange to me, since there is no 'account' to be disabled: I wasn't even presented with a login dialog. (The account that I would have used isn't disabled...)

The client (the one with the error message) is running Windows XP SP3. The server is running Windows 7; its firewall is set to allow file sharing from any computer in our /16 CIDR (the client, naturally, is in this large block).

How can I get the server to recognize the client? I can change settings on either.

It sounds like your client machine is not giving you the opportunity to specify credentials for the "share" username that you have created on your server.

In a workgroup environment, the easiest way to force Windows to log into a network share with specific credentials is as follows:

net use \\server\share /delete
net use \\server\share /user:server\username <password>

Mapping a drive letter to the share is optional, e.g.:

net use \\server\share /delete
net use S: /delete
net use S: \\server\share /user:server\username <password>

In your specific case, the username above would be "share".

By the way: how many clients are accessing this "server" concurrently? Windows 7 has a limit of 20 connections, up from 10 in Windows XP. It's been a long time since I've worked in an environment that was using a Windows client OS as a file server, but it seems plausible that, if the limit were reached, additional connections could be denied with a non-intuitive error message.

Take a look at the Credential Manager on the XP machine.

Control Panel -> User Accounts -> Manage My Network Passwords (on left of screen)

Here you will see a list of stored usernames\passwords and the server\share that they are used against.

Delete the server\share in question, and next time you connect to the share it should prompt you for a username and password.

Edit:

Another thing to check would be the number of open sessions on the Windows 7 machine hosting the share. Windows 7 has a limit of 10 concurrent sessions.

You can check this in computer management on the Windows 7 machine -

On the start menu right click "computer" and choose manage, then navigate to System Tools - Shared folders - Open Sessions.

This is caused by there not being a password on your account on the pc you are trying to connect From

Click through Control Panel - user accounts and set a password for your current login

then when you try to access the network share it will prompt for a username and password. use the correct one to access the share at this point.

Try typing 'net use' at the command prompt and see if any credentials for that server have been cached and delete accordingly.