Process list can be retrieved from local machine and remote computers. Anyway, you need to have administrative privileges on remote PCs to get their process list. Job is done using WMI. This is the relevant code:

ConnectionOptions options = new ConnectionOptions();

options.Authentication = AuthenticationLevel.Call;
options.Impersonation = ImpersonationLevel.Impersonate;
options.EnablePrivileges = true;

// We don't need to use credentials on local machine
if (!((strServer.CompareTo(".") != 0)

    || (String.Compare(strServer, System.Environment.MachineName,

    true) != 0)))
{
    options.Username = strUsername;
    options.Password = strPassword;
}

ManagementScope ms = new ManagementScope(@"\\"
    + strServer + @"\root\CIMV2", options); ms.Connect();

    SelectQuery myQuery = new SelectQuery("Win32_Process");
ManagementObjectSearcher query =
    new ManagementObjectSearcher(ms, myQuery);

runningProcesses = query.Get();

When enumerating is complete, a RegEx is applied to seek desired processes.
Process objects are wrapped in custom objects, so the can be sorted implementing IComparer.
Process list can be represented in a flat style or in a tree view. Tree shows process hierarchy.