[[maeyanes]]

Usa la función GetComputerName del API de Windows...

Código Delphi [-]
var
  PCName: PChar;
  NameSize: DWord;

begin
  NameSize := MAX_COMPUTERNAME_LENGTH + 1; 
  // MAX_COMPUTERNAME_LENGTH es una constante definida en Windows.pas
  PCName := strAlloc(NameSize);
  GetComputerName(PCName, NameSize)
end;