Listing thin client drives in a Windows Terminal 2003

I think you need to enumerate the network resources, checking which resource is a disk resource. Take this piece of code, for example:

program GetNetShares;

{$APPTYPE CONSOLE}

uses
  Windows, SysUtils;

const
  NERR_Success = 0; // Success

type
  NET_API_STATUS = DWORD;
  PShare_Info_0 = ^TShare_Info_0;
  TShare_Info_0 = record
    shi0_netname: PWideChar;
  end;
  PShare_Info_0_Arr = ^TShare_Info_0_Arr;
  TShare_Info_0_Arr = array[0..MaxInt div SizeOf(TShare_Info_0) - 1] of TShare_Info_0;
  PShare_Info_1 = ^TShare_Info_1;
  TShare_Info_1 = record
    shi1_netname: PWideChar;
    shi1_type: DWORD;
    shi1_remark: PWideChar;
  end;
  PShare_Info_1_Arr = ^TShare_Info_1_Arr;
  TShare_Info_1_Arr = array[0..MaxInt div SizeOf(TShare_Info_1) - 1] of TShare_Info_1;
  PShare_Info_2 = ^TShare_Info_2;
  TShare_Info_2 = record
    shi2_netname: PWideChar;
    shi2_type: DWORD;
    shi2_remark: PWideChar;
    shi2_permissions: DWORD;
    shi2_max_uses: DWORD;
    shi2_current_uses: DWORD;
    shi2_path: PWideChar;
    shi2_passwd: PWideChar;
  end;
  PShare_Info_2_Arr = ^TShare_Info_2_Arr;
  TShare_Info_2_Arr = array[0..MaxInt div SizeOf(TShare_Info_2) - 1] of TShare_Info_2;
  PShare_Info_502 = ^TShare_Info_502;
  TShare_Info_502 = record
    shi502_netname: PWideChar;
    shi502_type: DWORD;
    shi502_remark: PWideChar;
    shi502_permissions: DWORD;
    shi502_max_uses: DWORD;
    shi502_current_uses: DWORD;
    shi502_path: PWideChar;
    shi502_passwd: PWideChar;
    shi502_reserved: DWORD;
    shi502_security_descriptor: PSECURITY_DESCRIPTOR;
  end;
  PShare_Info_1004 = ^TShare_Info_1004;
  TShare_Info_1004 = record
    shi1004_remark: PWideChar;
  end;
  PShare_Info_1006 = ^TShare_Info_1006;
  TShare_Info_1006 = record
    shi1006_max_uses: DWORD;
  end;
  PShare_Info_1501 = ^TShare_Info_1501;
  TShare_Info_1501 = record
    shi1501_reserved: DWORD;
    shi1501_security_descriptor: PSECURITY_DESCRIPTOR;
  end;

function NetShareEnum(servername: PWideChar; level: DWORD; var buf: Pointer; prefmaxlen: DWORD; var entriesread: DWORD; var totalentries: DWORD; var resume_handle: DWORD): NET_API_STATUS; stdcall; external 'netapi32.dll';

function NetShareGetInfo(servername: PWideChar; netname: PWideChar; level: DWORD; var buf: Pointer): NET_API_STATUS; stdcall; external 'netapi32.dll';

function NetApiBufferFree(P: Pointer): NET_API_STATUS; stdcall; external 'netapi32.dll';

var
  Server: PWideChar;
  Buffer, Loop: PShare_Info_0;
  Buf502: PShare_Info_502;
  NetResult: DWORD;
  entriesread: DWORD;
  totalentries: DWORD;
  resume_handle: DWORD;
  I: Integer;
begin
  if (ParamCount = 0) then begin
    Server := nil;
  end
  else begin
    Server := PWideChar(WideString(ParamStr(1)));
  end;
  entriesread := 0;
  totalentries := 0;
  resume_handle := 0;
  NetResult := NetShareEnum(Server, 0, Pointer(Buffer), DWORD(-1), entriesread, totalentries, resume_handle);
  if (NetResult = NERR_Success) then begin
    Loop := Buffer;
    WriteLn('Entries read: ', entriesread);
    for I := 1 to entriesread do begin
      WriteLn('Name: ', string(Loop.shi0_netname));
      try
        NetResult := NetShareGetInfo(Server, Loop.shi0_netname, 502, Pointer(Buf502));
        if (NetResult = NERR_Success) then begin
          WriteLn('* Net name: ', string(Buf502.shi502_netname));
          WriteLn('* Type: ', Buf502.shi502_type);
          WriteLn('* Remark: ', string(Buf502.shi502_remark));
          WriteLn('* Permissions: ', Buf502.shi502_permissions);
          WriteLn('* Max uses: ', Buf502.shi502_max_uses);
          WriteLn('* Current uses: ', Buf502.shi502_current_uses);
          WriteLn('* Path: ', string(Buf502.shi502_path));
          WriteLn('* Password: ', string(Buf502.shi502_passwd));
          WriteLn('* Reserved: ', Buf502.shi502_reserved);
        end
        else begin
          WriteLn('* Error: ', SysErrorMessage(NetResult));
        end;
        NetApiBufferFree(Buf502);
      except on E: Exception do WriteLn('* Error: ', E.Message);
      end;
      WriteLn;
      Inc(Loop);
    end;
    NetApiBufferFree(Buffer);
  end;
end.

Basically, the only thing you need to know is the Path for all disk resources. It should work, technicakky speaking.

     Thanks for your code , but it does not work in Terminal Server 2003 (RDP session). This is the kind of problem I have experimented with some API functions that "only see" mapped network drives but not those shared in a Terminal Server session.

      When a RDP session is  stablished and its local resources are exposed, all the entire drives appear with next format in Windows Explorer: Drive + 'ON ' + Machine_Name, example:
                    A On LapTop.
                    C On LapTop.

Thanks

Another option could be the use of WMI. I'll include some example that I used in a console application:

program GetShares;

{$APPTYPE CONSOLE}

uses
  Windows, SysUtils, ActiveX, WbemScripting_TLB;

function NextItem(var Enum: IEnumVARIANT; const riid: TGUID; out ppObject): Boolean;
var
  OleProperty: OleVariant;
  NumProp: LongWord;
begin
  try
    Result := Succeeded(Enum.Next(1, OleProperty, NumProp)) and (NumProp > 0) and Succeeded(IDispatch(OleProperty).QueryInterface(riid, ppObject));
  except
    Result := False;
    IUnknown(ppObject) := nil;
  end;
end;

function Prop(Obj: ISWbemObject; Name: string): string;
begin
  try
    Result := VarToStr(obj.Properties_.Item(Name, 0).Get_Value);
  except on E: Exception do Result := E.Message;
  end;
end;

var
  AFile: TextFile;
  Enum: IEnumVARIANT;
  Obj: ISWbemObject;
begin
  if Succeeded(CoInitializeEx(nil, COINIT_MULTITHREADED or COINIT_DISABLE_OLE1DDE or COINIT_SPEED_OVER_MEMORY)) then begin
    AssignFile(AFile, ChangeFileExt(ParamStr(0), '.txt'));
    Rewrite(AFile);
    try
      Enum := CoSWbemLocator.Create.ConnectServer(ParamStr(1), 'root\cimv2', '', '', '', '', 0, nil).ExecQuery('Select * from Win32_Share', 'WQL', wbemFlagBidirectional, nil)._NewEnum as IEnumVariant;
      while NextItem(Enum, SWBemObject, Obj) do begin
        WriteLn('Name: ', Prop(Obj, 'Name'));
        WriteLn(AFile, 'Name: ', Prop(Obj, 'Name'));
        WriteLn(AFile, 'Path: ', Prop(Obj, 'Path'));
        WriteLn(AFile, 'Status: ', Prop(Obj, 'Status'));
        WriteLn(AFile, 'Caption: ', Prop(Obj, 'Caption'));
        WriteLn(AFile, 'Description: ', Prop(Obj, 'Description'));
        WriteLn(AFile, 'AllowMaximum: ', Prop(Obj, 'AllowMaximum'));
        WriteLn(AFile);
        obj := nil;
      end;
    except
      on E: Exception do begin
        WriteLn(E.Message);
        WriteLn(AFile, E.Message);
      end;
    end;
    Enum := nil;
    CoUninitialize;
    CloseFile(AFile);
  end;
end.

To get the unit WbemScripting_TLB all you have to do is "Project/Import type library" and add the file "C:\WINNT\system32\wbem\wbemdisp.tlb" to Delphi. If possible, don't let it create a component wrapper since it's not much use anyway. Like the other application, this is just a simple console application. Let me know if you need the WbemScripting_TLB too, or grab it from http://workshop-alex.org/Sources/WbemScripting_TLB.pas if you use Delphi 7.
I would assume that of all system environment thingies, WMI would always provide the required information. If it doesn't then I assume there's no way to retrieve the information.

 Workshop_Alex,

  Thanks for taking a time to try to help me with this question and I would like to tell you that it works because your effort but unfortunately again it didn't work.  

Regards