[Code]
var
  // dotNetBool is not descriptive
  DotNetInstalled: Boolean;

function InitializeSetup: Boolean;
begin
  // store the detected state
  DotNetInstalled := RegKeyExists(HKLM, 'SOFTWARE\Microsoft\.NETFramework\policy\v4.0');
  // continue if .NET is installed, or (if not) the user agreed to continue
  Result := DotNetInstalled or (MsgBox('.NET not installed. Continue ?', mbConfirmation, MB_YESNO) = IDYES);
end;

function IsDotNetInstalled: Boolean;
begin
  Result := DotNetInstalled;
end;