Delete prefs file fixes connect to Windows Server problem:

a follow-up Regarding our previous item on a Windows Server connect problem, Philip Lamb explains:

"The problem arises if the user at any time disables the 'Allow clear text passwords' option when presented with any server login password request. Although Macs will use other authentication methods, some windows servers refuse to allow AFP connections except with clear text passwords, and so when the user later tries to connect to such a server, he or she gets the 'No file services are available' error message, without even seeing the login box from where the problem could be fixed!

The fix is to connect to a different server (one that doesn't use clear-text passwords) and when logging in, re-enable sending of clear-text passwords from the options button on the login box. Deleting the preferences file com.apple.AppleShareClientCore.plist has the same effect."

Update: Remo Del Bello writes: "Another way around this, particularly if you don't have access to another file server, is to delete the keychain entry for the particular server. This will cause the login dialog to appear the next time you try to log-in at which point one can select to re-enable the clear-text option."