Restart the Server (LanmanServer) service, restart ESF on the Android device, browse to LAN connection, done. Doesn't require plain text passwords or any other registry hack.
Make note of any dependent services that may also need to be restarted:
The following services are dependent on the Server service.
Stopping the Server service will also stop these services.
Do you want to continue this operation? (Y/N)
On Android, make sure ES File Explorer is closed completely, not just exited (suspended). Samsung's [Close All] seems to be effective (don't remember the Nexus equivalent).
Start >> Run >> Services.msc >> select "Server" and Restart
Sc \\server stop LanmanServer
Sc \\server start LanmanServer
a.k.a sources a.k.a. other paths which might be fruitful for you if the above isn't.
Suggestion: Enable Plain Text Passwords in Windows
…you could attempt to enable plaintext SMB authentication just to see if it fixes your problem, though. Its unclear to me whether this would work on Windows 7 or not, but you could try setting the DWORD value "EnablePlainTextPassword" to "1" at "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkStation\Parameters". Reboot (or stop and restart the "Workstation" service) and see what that does.
Check out Chris S comment below. It's very likely that the default LMCompatibilityLevel of Windows 7 (which is "3", meaning "Send NTLMv2 only") is causing your problem if your LaCie device is using an older SMB server (like a Samba version pre-3.0.21, for example).
This is what I did last time this irritated me enough to do something. However when I checked that setting now, it's still set.
Suggestion: Reboot Server
…a dirty workaround: reboot your Windows file server. All your Android devices will immediately be able to connect again... for a time being. For me it usually lasts 1-2 days. Then SOMETHING happens - obviously on the Windows side, and it's again "login fails" from all Androids with ES, yet Windows machines keep being able to access all the shares.
Suggestion: Re-enable SMB Protocol
I had the same problem and fixed it by reenabling the SMB protocol as described here:
To enable or disable SMB protocols on an SMB Server that is runningWindows 7, Windows Server 2008 R2, Windows Vista, or Windows Server 2008, use Windows PowerShell or Registry Editor. […] paste the following cmdlet into the powershell:
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" SMB2 -Type DWORD -Value 1 -Force
and hit enter. Reboot.
Suggestion: Enable Server File Sharing Mode
WIN7 machines when left on for a while, tend to have their shares just "disappear". There are registry setting that can fix this PC to PC problem […] in the release of WIN7. […] They changed the numbers in two registry settings, and that caused your PC-to-PC shares (in your home network which has no server) to disappear. […] By changing the registry BACK to normal settings, you essentially tell it to act like all the other versions of Windows did. The recommended settings for a machine that has shares in use, is
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\LargeSystemCache=1
An answer on Super User to Connect from Android (ES File Explorer) to Windows 7 Share suggests the same.