Andrew Seaford

To check that DotNet framework is installed during an Inno install. Add the following code section to the install script.

; Check if dot net is insalled
[code]
function FrameworkIsNotInstalled: Boolean;
begin
Result := not RegKeyExists(HKEY_LOCAL_MACHINE, 'Software\Microsoft\.NETFramework\policy\v4.0');
end;

// Install dot net with feedback
[Code]
procedure InstallFramework;
var
StatusText: string;
ResultCode: Integer;
begin
StatusText := WizardForm.StatusLabel.Caption;
WizardForm.StatusLabel.Caption := 'Installing .NET framework...';
WizardForm.ProgressGauge.Style := npbstMarquee;
try
if not Exec(ExpandConstant('{tmp}\dotNetFx40_Full_x86_x64.exe'), '/q /noreboot', '', SW_SHOW, ewWaitUntilTerminated, ResultCode) then
begin
// you can interact with the user that the installation failed
MsgBox('.NET installation failed with code: ' + IntToStr(ResultCode) + '.',
mbError, MB_OK);
end;
finally
WizardForm.StatusLabel.Caption := StatusText;
WizardForm.ProgressGauge.Style := npbstNormal;
end;
end;

In the files section add the dotnet installer file. Note the flags AfterInstall and Check that will call the functions to check if DotNet is installed and instal if required.

Source: "C:\Example\dotNetFx40_Full_x86_x64.exe"; DestDir: {tmp}; Flags: deleteafterinstall; AfterInstall: InstallFramework; Check: FrameworkIsNotInstalled

Download the installer script CheckDotNet.iss