Cannot access workspace of the user in new server when trying to shift the TFS server to another PC

We are using TFS 2012. All the PC are connected by using Workgroup.(we are not using domain). The TFS PC is having PC name as PCTFS . We have about 15 developers who use TFS. As we use workgroup so we have created all windows users of 15 developers in the TFS server pc. So now TFS server PC has windows users like PCTFS\user1 , PCTFS\user2 ,PCTFS\user3 so on.

All these users connect to TFS server PC from their PC. As they have same user created in TFS server PC the authentication works by matching windows user name. So developer can connect to TFS server and work on it. Each user has its own permissions like create workspace , shelveset, chekin permission etc.

When trying to shift the TFS server to another PC. So PC name having TFS installed will change from PCTFS to PCNEWTFS . So when After restoring the sql databases of all collection.

So , First we remapped using : TFSConfig RemapDBs /DatabaseName:PCNEWTFS\SQLEXPRESS;TFS_Configuration /SQLInstances:PCNEWTFS\SQLEXPRESS

Then we reset the owner using :

TFSConfig Accounts /ResetOwner /SQLInstance: PCNEWTFS \SQLEXPRESS /DatabaseName:TFS_Configuration

Then we added the account using :

TfsConfig Accounts /add/AccountType:ApplicationTier /account: PCNEWTFS \user1 /SQLInstance: PCNEWTFS \SQLEXPRESS /DatabaseName:Tfs_Configuration

At last we changed the identities using :

TFSConfig Identities /change /fromdomain: PCTFS /todomain: PCNEWTFS

All the operation were successful and all the newely created users are accessible after changing identities.

Like ,

   Account name                          Exists                  Matches 

   PCNEWTFS\user1                        True                    False 

Please help me in the following questions

We referred the following article .

1.When trying to access workspace of the user in new server all the workspaces are referring to old server they are not shifted to new server. How to make them refer new server ?

2.Should we add account for all the user using tfsconfig command ?

3.After changing the identities is there anything else to do ?

4.We have restored all the collection databases from the old SQL server and after restoring we get all the users under database security . But these users are not created in new SQL server under server security logins . Should we create new login for the user in SQL server or these users are added automatically when we run above commands etc.?