Mapped Network Drive with SMB1 and Windows 10 [closed]

I have a Windows Server 2003 machine (I know, but it’s out of my control) with a bunch of network shares on it. I have a laptop that has just been rebuilt with Windows 10 2004. I’ve enabled CIFS/SMB1 in the Windows Features dialogue and I can browse to the network shares OK using the UNC in File Explorer and via the Run prompt.

However, as soon as I map one of these shares as a network drive File Explorer fails to connect. If I click on one of the drives it just seems to hang Explorer and eventually times out (if I don’t force restart Explorer before that). Prior to the rebuild the laptop connected to the mapped drives fine even after being upgraded to Windows 10 2004, as do other laptops.

What am I missing that allows other laptops to connect to these drives? Are there any other settings that I should be using to resolve this?

I wrestled with this one today. The main points were:

1. Enable SMB1 support (run -> optionalfeatures -> SMB 1.0/CIFS File sharing support -> Client) and disable the Automatic removal feature.

2. Re-enable two services: "Function discovery resource publication" and "Function discovery Provider Host"

3. Create the following registry key:

   HKEY_CURRENT_USER\Network\(DRIVE_LETTER_HERE)\ProviderFlags
   type REG_DWORD and value 1

My starting point was an embedded CNC machining tool that runs 2k server and Windows 10 2004, explorer in Windows would completely freeze after attempting to connect the server, according the user it used to work before.

I tip my hat at Samuli for pointing me to the 3rd step that finally solved the whole thing.

Edit: Be sure to add the registry value to every mapped drive in case you have more than one.