The HomeGroup networking program in Windows 10 needs some work. It is a good idea which makes networking home computers much easier that networking them the old fashioned way. However, it looks like HomeGroup runs into trouble when the original PC on which it was set up leaves the network, and nobody knows the old password.
When you try to start up a HomeGroup connection or add a new PC to the HomeGroup, the program says that there is a group that you can join, but then it says the link fails. If you try to leave the old network and create a new one, you can’t.
There are a number of suggestions about how to resolve this problem in chatrooms and on websites offering advice on Windows. Usually you can get HomeGroup working again, but not easily.
One approach that seems to work sometimes, but not always, is to turn off all the computers on the network except one. Tell it to leave the HomeGroup, and then try to create a new HomeGroup. The trouble that often occurs is that it won’t let you create a new group; it says you have to join the old group. If you start with a brand new computer that has never been on the network, the new HomeGroup will probably work. You can then get the password that the new computer uses for the group and then use it to log in the older computers.
Microsoft needs to work on this problem. I suppose they want to force you to have only one HomeGroup on a network, but they should make it possible to create a new one to replace the old one, if the old one is not working.