Enable or Disable SMB 2 and/or SMB 3 on Clients and Servers. SMB is the file sharing protocol used by default on Windows-based computers. SMB 1 was designed for early Windows network operating systems such as Microsoft LAN Manager and Windows for Workgroups, but until Windows Server 2008 and Vista, all Microsoft-based operating systems continued to use it more or less in its original format. SMB 2 was introduced in Windows Vista and Windows Server 2008. SMB 3 was introduced in Windows 8 and Windows Server 2012. Windows Vista/7/8/10 can act as a server and Windows 2008(R2) and 2012(R2) can act as a client. SMB 2 and SMB 3 is designed for the needs of the next generation of file servers. Windows Server 2008 (R2), Windows Vista and Windows 7 supports both SMB 1 and SMB 2 in order to preserve backward compatibility. The same applies to newer versions of Windows.