In Windows 10 Fall Creators Update and Windows Server, version 1709 (RS3), the Server Message Block version 1 (SMBv1) network protocol is no longer installed by default.
We spotted this recently at one of our customer’s site whereby a logon script was no longer mapping a particular network drive to an old NAS device and coming up with the following error;
You can’t connect to the file share because it’s not secure. This share requires the obsolete SMB1 protocol, which is unsafe and could expose your system to attack.
How to enable SMBv1
Microsoft have removed this feature for security reasons as SMBv1 is not very secure but if you do however need to enable access to older devices then you can enable the feature by doing the following;
Go to Control Panel > Programs and Features > Turn Windows Features on or off > check or uncheck the box for “SMB 1.0/CIFS File Sharing Support”
More information can be found here