I recently upgraded all three of my network PCs to Windows 10 (two of them were windows 7 and one was Windows 8), and the file sharing I had in place stopped working (it was based on all the PCs having the same login details on being in a Workgroup). I figured I'd set up a Homegroup and have sharing work that way, since it seems much easier now that my logins don't match (each person uses their email login to their own computer).
The problem is that when I click "Join a homegroup", I see that a homegroup has been created by a PC we no longer have on our network. I can't ping the name, and the desktop to which this name belongs was reformatted years ago. When I attempt to join the group anyways, I'm prompted for the password (which I don't know and can't see, as none of the PCs are part of this homegroup), and then it hangs indefinitely. I also can't see any way to pick a "Start a new homegroup, ignore this existing one" type option to just start over.
Is there any way to start a brand new homegroup? Barring that, where is this computer name (which doesn't exist anymore) being kept as the authoritative keeper of my existing homegroup so that I can wipe it out?