The name of this computer is established at system startup when the name is read from the registry. If this computer is a node in a cluster, the name of the node is returned.

The following example displays the name of the computer that runs the code example. (The machine name is omitted from the example output for security reasons.)

' Sample for the Environment.MachineName property
Imports System

Class Sample
   Public Shared Sub Main()
      Console.WriteLine()
      '  <-- Keep this information secure! -->
      Console.WriteLine("MachineName: {0}", Environment.MachineName)
   End Sub 'Main
End Class 'Sample
'
'This example produces the following results:
'(Any result that is lengthy, specific to the machine on which this sample was tested, 
'or reveals information that should remain secure, has been omitted 
'and marked "!---OMITTED---!".)
'
'MachineName: !---OMITTED---!
'

• EnvironmentPermission 

  for read access to the COMPUTERNAME environment variable. Associated enumeration: EnvironmentPermissionAccess.Read

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role not supported), Windows Server 2003 SP2

.NET Framework

.NET Framework Client Profile

Reference