I've been doing battle with this issue for years... I got back to it when I moved a work computer home and tried to set up network shares. Both computers were showing in Windows Explorer "Network," but then one or both disappeared when I updated Windows10. All the "easy" networking settings are correct, and I enabled services as recommended... One computer was showing up, but the other was not... not even to itself...
I followed one recommendation to turn on network discovery via the command line, and it actually turned off network discovery... not sure why. I reset network, restarted computer, and the missing Computer under "Network" was now showing... which gets me to the credential issue.
I still haven't solved this when clicking
in the Network explorer
Same credential error when I enter \T3600 in the address line.
HOWEVER!!!!
When I enter the entire path to the folder share \T3600\Photos, it opens without asking for credentials!!!
UPDATE: Unfortunately, this quit working... I had tried the same approach from T3600 the other computer (it didn't work), and when I came back I could not access the Photos folder on T3600. Strange behavior!
UPDATE2: Now it's working again... from both computers... don't know why... Strange thing - when using the direct path method, the folder is VERY slow to open.
I have this exact same issue!
I put all my media on my laptop on a connected external HD. I share a folder on that HD and if I go directly to the video folder (//laptop/videos) I can access it. But for some reason I can't get to the folder through the root //laptop folder .... I get the permission issue. And I have no idea what my login would be because my microsoft account is set up without a password, just authenticator and PIN to login to windows.
And until my computer did some updates last night, this had never been an issue. So frustrating. Have gone through every 'problem solving' thing google can come up with and nothing works to get access to that default shared folder.
EDIT: after much sweat and pain I finally figured out a solution for myself. I had to change my microsoft account that I initially signed into windows using - to an account with a password (was previously 2fa and no password). Once my account had a password, I was able to create a user login for my default user, which I was ultimately able to use to log in to my computer over the network. It seems that the key is having a user/password for your default windows login that can subsequently be used to access the shared drives from the network. Just about locked myself out of the computer in the process, but it works now.