If you are planning to Disable SMBv1 with Group Policy, Microsoft has made it even easier for you. In the latest Security Baseline,“Creators Update” (v1703), Microsoft released “MS Security Guide” ADMX template, with which you can configure SMBv1 for Client and Server, via Group Policy. In order to set it to work, copy SecGuide.admx into your Central Store PolicyDefinitions directory, and SecGuide.adml into the en-us subdirectory.
Warning: Do not disable SMBv1 if you are using old OS, like Windows XP and Windows 2003 in your environment (If you are using those old and expired OS, you are not secure anyway!).
Read Microsoft’s article for Disabling SMBv1 through Group Policy , before changing anything and please notice the BIG warning about the Configure SMBv1 client extra setting, WARNING: DO NOT SELECT THE “DISABLED” RADIO BUTTON UNDER ANY CIRCUMSTANCES!
SMBv1 is very old, almost 30 years old and is used only by old OS, Windows XP / Windows Server 2000 and older. Since Windows Vista / Windows Server 2008, Microsoft introduced SMB 2.0 version and then SMB 2.1 with Windows 7 / Windows Server 2008 R2. With Windows 8 / Windows Server 2012 SMB 3.0 made its appearance and then SMB 3.0.2 in Windows 8.1 / Windows Server 2012 R2. The latest version of SMB is SMB 3.1.1, which was introduced with Windows 10 and Windows Server 2016.
SMBv1 is not secure at all and even its owner, Ned Pyle, is begging you to stop using it in his article, Stop using SMB1