As with Windows 8 and 8.1 accessing legacy (Win 2k3 Server) file shares, Windows 10 requires a bit of tweaking. It is slightly different than Windows 8.
- Press the Win Key + r
- Type regedit <enter>
- Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
- Create the following values if they do not exist
- NAME: RequireSecureNegotiate TYPE: REG_QWORD VALUE: 2
- NAME: RequireSecuritySignature TYPE: REG_DWORD VALUE: 2