Question

EDIT

I still can’t assign the process the username of the session id that is associated with it.

This is the code i use to retrieve user details:

    Public Sub GetUsers()
    Using server As ITerminalServer = manager.GetRemoteServer(strHostName)
        server.Open()
        For Each session As ITerminalServicesSession In server.GetSessions()
            If Not String.IsNullOrEmpty(session.UserName) Then
                dictuser.Add(session.SessionId, New User(session.SessionId, session.UserName))
            End If
        Next
    End Using
End Sub

my user class is defined simply as:

Public Class User
Private _SessionID As Integer
Private _UserName As String

Sub New(ByVal SessionID As Integer, ByVal UserName As String)
    _SessionID = SessionID
    _UserName = UserName
End Sub

Public ReadOnly Property SessionID As String
    Get
        Return _SessionID
    End Get
End Property

Public ReadOnly Property UserName As String
    Get
        Return _UserName
    End Get
End Property
End Class

i have created a function in my process class:

Public Sub AddUserInfo(ByVal UserName As String)
    _UserName = UserName
End Sub

Answer 1

This replaces the process if a process with the same id is found in the dictionary and automatically adds a new process otherwise.

dictProcess(process.ProcessId) = process

---

EDIT (in response to your edited question):

I would change the name of the Processes class to Process, since it is not a collection, but is supposed to represent one process. You could change the constructor of the Process class to

Public Sub New(ByVal ProcessId As Integer, ByVal ProcessName As String, ByVal SessionId As Integer)            
    _ProcessId = ProcessId            
    _ProcessName = ProcessName            
    _SessionId = SessionId            
End Sub

Then add a method

Public Sub AddWmiInfo (ByVal PageFileUsage As Integer, ByVal WorkingSetSize As Integer)
    _PageFileUsage = PageFileUsage            
    _WorkingSetSize = WorkingSetSize            
End Sub

Alternatively, you could also make these properties read/write, however you get a better encapsulation like this.

Add the basic process information to the dictionary using Cassia. Note that ProcessId is declared as Integer and thus the check Not String.IsNullOrEmpty(process.ProcessId) makes no sense.

For Each process As ITerminalServicesProcess In server.GetProcesses()                       
    dictprocess.Add( _
      process.ProcessId, _
      New Process(process.ProcessId, process.ProcessName, process.SessionId))                       
Next

Finally, you would add the information from the WMI like this

Dim p As Process = Nothing
For Each wmiProcess In prowmi
    If dictprocess.TryGetValue(wmiProcess.ProcessID, p) Then
        p.AddWmiInfo(wmiProcess.PageFileUsage, wmiProcess.WorkingSetSize)
    End If
Next

TryGetValue returns a process in the variable p. The second parameter of TryGetValue is a ByRef parameter.

---

EDIt #2:

Your loop should read

Dim p As Process = Nothing
For Each user As User In dictuser.Values
    If dictprocess.TryGetValue(user.SessionID, p) Then
        p.AddUserInfo(user.UserName)
    End If
Next

However, if you are never accessing the user dictionary through the key (session id), then a list would be more appropriate than a dictionary.