win 7 win-eplorer does not remember group members / network sources

[Gunter]

Hi there,
I am new member to this forum in terms of posting. I've retrieved / found here some valuable hints for my win 7 machine issues in the past.

Currently I am running into an issue with my win 7 file explorer, arising after a network troubleshooter use ...
The left pane, Network section of my explorer window will now show only:

This machine itself
My LAN router

It was showing all my LAN members before.
I can however go to other workgroup members / shared sources,
by entering their names in address bar e.g. \\name

which will result in the source being listed in the Network section.
However, after closing and restarting the file explorer (or reboot) these entries will be lost again.

Yes, all members are in the same workgroup, with sharing active.
Setting back the system to an restore point before the troubleshooter date did not resolve the issue.
The win 7 machine programs and features menue does not show any smb entry
and manually editing the registry (adding) a SMB1 key (value 1) resulted in completely freezing the system.

Anybody out there who can give a hint to an existing thread or direct advice ??

Any help appreciated
best regards
Gunter