How to remove custom wizard input field inno setup?

so I know you can add a custom field with the .add method...is there any way to REMOVE one?

The reason is I'm only adding the fields if a component is selected, and if the user goes back I want to remove the fields, so that they don't multiply. :)

Thanks!

Here's my .iss: (I was planning to put the code in the OnBackButtonClick function...that's why it's there ;)

; Script generated by the Inno Setup Script Wizard.
; SEE THE DOCUMENTATION FOR DETAILS ON CREATING INNO SETUP SCRIPT FILES!

#define MyAppName "DXX-Rebirth"
#define MyAppName1 "D1X-Rebirth"
#define MyAppName2 "D2X-Rebirth"
#define MyAppVersion "0.57.0"
#define MyAppURL "http://www.dxx-rebirth.com/"
#define MyAppExeName "d1x-rebirth.exe"
#define MyAppExeName2 "d2x-rebirth.exe"

[Setup]
; NOTE: The value of AppId uniquely identifies this application.
; Do not use the same AppId value in installers for other applications.
; (To generate a new GUID, click Tools | Generate GUID inside the IDE.)
AppId={{DF665ED8-D2A7-490A-805F-6677EFFBAB40}
AppName={#MyAppName}
AppVersion={#MyAppVersion}
;AppVerName={#MyAppName} {#MyAppVersion}
AppPublisherURL={#MyAppURL}
AppSupportURL={#MyAppURL}
AppUpdatesURL={#MyAppURL}
DefaultDirName={pf}\{#MyAppName}
DefaultGroupName={#MyAppName}
OutputBaseFilename=Setup
Compression=lzma
SolidCompression=yes

[Languages]
Name: "english"; MessagesFile: "compiler:Default.isl"
Name: "german"; MessagesFile: "compiler:Languages\German.isl"

[Tasks]
Name: "desktopicon"; Description: "{cm:CreateDesktopIcon}"; GroupDescription: "{cm:AdditionalIcons}";
Name: "quicklaunchicon"; Description: "{cm:CreateQuickLaunchIcon}"; GroupDescription: "{cm:AdditionalIcons}"; Flags: unchecked

[Types]
Name: "install"; Description: "DXX-Rebirth"; Flags: iscustom

[Components]
Name: "d1x"; Description: "D1X"; Types: install
Name: "d2x"; Description: "D2X"; Types: install

[Files]
;D1X Files
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\d1x-rebirth.exe"; DestDir: "{app}\D1X-Rebirth"; Components: d1x; Flags: ignoreversion
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\*"; DestDir: "{app}\D1X-Rebirth"; Excludes: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Missions,C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Players,C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Demos,C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Screenchots"; Components: d1x; Flags: ignoreversion recursesubdirs createallsubdirs
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Missions"; DestDir: "{app}\D1X-Rebirth"; Components: d1x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Players"; DestDir: "{app}\D1X-Rebirth"; Components: d1x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Demos"; DestDir: "{app}\D1X-Rebirth"; Components: d1x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d1x-rebirth_v0.57-win\d1x-rebirth_v0.57-win\Screenshots"; DestDir: "{app}\D1X-Rebirth"; Components: d1x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
;D1 Main Files
Source: "{code:Descent}\descent.hog"; DestDir: "{app}\D1X-Rebirth"; Components: "d1x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\descent.pig"; DestDir: "{app}\D1X-Rebirth"; Components: "d1x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
;D1 Missions
Source: "{code:Descent}\*.hog"; DestDir: "{app}\D1X-Rebirth\Missions"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.msn"; DestDir: "{app}\D1X-Rebirth\Missions"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.rdl"; DestDir: "{app}\D1X-Rebirth\Missions"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Missions\*"; DestDir: "{app}\D1X-Rebirth\Missions"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\descent.hog"; DestDir: "{app}\D1X-Rebirth\Missions"; Components: "d1x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist deleteafterinstall
;D1 Players
Source: "{code:Descent}\*.eff:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.plr:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.plx:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.ngp:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.sg*:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\*.mg*:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.eff:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.plr:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.plx:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.ngp:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.sg*:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:Descent}\Players\*.mg*:"; DestDir: "{app}\D1X-Rebirth\Players"; Components: "d1x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
;D2X Files
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\d2x-rebirth.exe"; DestDir: "{app}\D2X-Rebirth"; Components: d2x; Flags: ignoreversion
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\*"; DestDir: "{app}\D2X-Rebirth"; Excludes: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Missions,C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Players,C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Demos,C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Screenshots"; Components: d2x; Flags: ignoreversion recursesubdirs createallsubdirs
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Missions"; DestDir: "{app}\D2X-Rebirth"; Components: d2x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Players"; DestDir: "{app}\D2X-Rebirth"; Components: d2x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Demos"; DestDir: "{app}\D2X-Rebirth"; Components: d2x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
Source: "C:\Documents and Settings\Owner\Desktop\Downloads\d2x-rebirth_v0.57-win\d2x-rebirth_v0.57-win\Screenshots"; Des开发者_运维百科tDir: "{app}\D2X-Rebirth"; Components: d2x; Flags: ignoreversion recursesubdirs createallsubdirs onlyifdoesntexist
;D2 Main Files
Source: "{code:DescentTwo}\descent2.ham"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\descent2.hog"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\descent2.s11"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\descent2.s22"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\alien1.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\alien2.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\fire.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\groupa.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\ice.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\water.pig"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\intro-h.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\intro-l.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\other-h.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\other-l.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\robots-h.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\robots-l.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
;Vertigo
Source: "{code:DescentTwo}\d2x-h.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\d2x-l.mvl"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\hoard.ham"; DestDir: "{app}\D2X-Rebirth"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\d2x.hog"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\d2x.mn2"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Missions\d2x.hog"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Missions\d2x.mn2"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist
;D2 Missions
Source: "{code:DescentTwo}\*.hog"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.mn2"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Missions\*"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\descent2.hog"; DestDir: "{app}\D2X-Rebirth\Missions"; Components: "d2x"; Check: not DontInstall; Flags: external skipifsourcedoesntexist deleteafterinstall
;D2 Players
Source: "{code:DescentTwo}\*.eff:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.plr:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.plx:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.ngp:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.sg*:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\*.mg*:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.eff:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.plr:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.plx:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.ngp:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.sg*:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
Source: "{code:DescentTwo}\Players\*.mg*:"; DestDir: "{app}\D2X-Rebirth\Players"; Components: "d2x"; Check: InstallAll; Flags: external skipifsourcedoesntexist
; NOTE: Don't use "Flags: ignoreversion" on any shared system files

[Icons]
Name: "{group}\{#MyAppName1}"; Filename: "{app}\D1X-Rebirth\{#MyAppExeName}"
Name: "{group}\{#MyAppName2}"; Filename: "{app}\D2X-Rebirth\{#MyAppExeName2}"
Name: "{group}\{cm:UninstallProgram,{#MyAppName}}"; Filename: "{uninstallexe}"
Name: "{userdesktop}\{#MyAppName1}"; Filename: "{app}\D1X-Rebirth\{#MyAppExeName}"; Tasks: desktopicon
Name: "{userdesktop}\{#MyAppName2}"; Filename: "{app}\D2X-Rebirth\{#MyAppExeName2}"; Tasks: desktopicon
Name: "{userappdata}\Microsoft\Internet Explorer\Quick Launch\{#MyAppName1}"; Filename: "{app}\D1X-Rebirth\{#MyAppExeName}"; Tasks: quicklaunchicon
Name: "{userappdata}\Microsoft\Internet Explorer\Quick Launch\{#MyAppName2}"; Filename: "{app}\D2X-Rebirth\{#MyAppExeName2}"; Tasks: quicklaunchicon

[Run]
Filename: "{app}\D1X-Rebirth\{#MyAppExeName}"; Description: "{cm:LaunchProgram,{#StringChange(MyAppName1, "&", "&&")}}"; Flags: nowait postinstall skipifsilent unchecked
Filename: "{app}\D2X-Rebirth\{#MyAppExeName2}"; Description: "{cm:LaunchProgram,{#StringChange(MyAppName2, "&", "&&")}}"; Flags: nowait postinstall skipifsilent unchecked

[UninstallDelete]
Type: filesandordirs; Name: "{app}"

[Code]
// global vars
var
  SampleDataPage: TInputOptionWizardPage;
  DataDirPage: TInputDirWizardPage;

// custom wizard page setup, for data dir.
procedure InitializeWizard;
begin
  { Taken from CodeDlg.iss example script }
  { Create custom pages to show during install }

  SampleDataPage := CreateInputOptionPage(wpSelectComponents,
    'Install Descent Data', '',
    'Would you like to copy the Descent game files to your DXX-Rebirth installation?',
    True, False);
  SampleDataPage.Add('Yes copy the game files, missions, players, and savegames.');
  SampleDataPage.Add('Yes, but just copy the game files.');
  SampleDataPage.Add('No, I'+chr(39)+'ll copy the game files myself later.');

  SampleDataPage.Values[0] := True;

  DataDirPage := CreateInputDirPage(SampleDataPage.ID,
  'Descent Data Directory', '',
  'Please select the location where the original Descent files are installed.',
  False, '');
end;

function NextButtonClick(CurPageID: Integer): Boolean;
begin
  if CurPageID = SampleDataPage.ID then
  begin
  if (IsComponentSelected('d1x') = true) and (IsComponentSelected('d2x') = true) then
    begin
      DataDirPage.Add('Descent location.');
      DataDirPage.Add('Decent 2 location.');
      DataDirPage.Values[0] := ExpandConstant('{pf}\GOG.com\Descent and Descent 2\Descent');
      DataDirPage.Values[1] := ExpandConstant('{pf}\GOG.com\Descent and Descent 2\Descent 2');
      result := true;
      exit;
    end;
    if (IsComponentSelected('d1x') = true) and (IsComponentSelected('d2x') = false) then
    begin
      DataDirPage.Add('Descent location.');
      DataDirPage.Values[0] := ExpandConstant('{pf}\GOG.com\Descent and Descent 2\Descent');
      result := true;
      exit;
    end;
    if (IsComponentSelected('d1x') = false) and (IsComponentSelected('d2x') = true) then
    begin
      DataDirPage.Add('Decent 2 location.');
      DataDirPage.Values[0] := ExpandConstant('{pf}\GOG.com\Descent and Descent 2\Descent 2');
      result := true;
      exit;
    end;
    result := true;
  end
  else
  begin
  result := true;
  end;  
end;

function BackButtonClick(CurPageID: Integer): Boolean;
begin
  if CurPageID = SampleDataPage.ID then
  begin
  result := true;
  end
  else
  result := true;
  end;
end;


function ShouldSkipPage(PageID: Integer): Boolean;
begin
  if (PageID = DataDirPage.ID) and (SampleDataPage.Values[2] = true) then
    Result := True
  else
    Result := False;
end;

function InstallAll(): Boolean;
begin
  { Return the value of the 'install' radiobutton }
  //MsgBox('InstallSampleData.', mbError, MB_OK);
  Result := SampleDataPage.Values[0];
end;

function Install(): Boolean;
begin
  { Return the value of the 'install' radiobutton }
  //MsgBox('InstallSampleData.', mbError, MB_OK);
  Result := SampleDataPage.Values[1];
end;

function DontInstall(): Boolean;
begin
  Result := SampleDataPage.Values[2];
end;

function DescentTwo(Param: String): String;
begin
if Assigned(DataDirPage) then
  begin
    if (IsComponentSelected('d1x') = true) and (IsComponentSelected('d2x') = true) then
    begin
      result := DataDirPage.Values[1];
    end;
    if (IsComponentSelected('d1x') = false) and (IsComponentSelected('d2x') = true) then
    begin
      result := DataDirPage.Values[0];
    end;
    if (IsComponentSelected('d1x') = true) and (IsComponentSelected('d2x') = false) then
    begin
      result := '';
    end;
  end
else 
 result := '';
end;

function Descent(Param: String): String;
begin
if Assigned(DataDirPage) then
  begin
    if (IsComponentSelected('d1x') = false) and (IsComponentSelected('d2x') = true) then
    begin
    result := '';
    end
    else
    begin
        result := DataDirPage.Values[0];
    end;
  end
  else   
   result := '';
  end;
end.

As you're using CreateInputDirPage(), the page is a TInputDirWizardPage. When you call .Add() it returns an index that you can use with the page's .Buttons[index], .Edits[index], and .PromptLabels[index] properties to get direct access to the controls themselves.

This then allows you to to set .Visible or .Enabled directly:

DataDirPage.PromptLabels[IndexToDisable].Enabled := false;
DataDirPage.Edits[IndexToDisable].Enabled := false;
DataDirPage.Buttons[IndexToDisable].Enabled := false;

The far better alternative though if there are more differences is to have two pages, and just skip one or the other in the ShouldSkipPage() event function.