We are checking in code for a registered pdf reader before we try to open a pdf file.
However, we are having problems on some machines that do not seem to be able to open the .pdf key in HKEY_CLASSES_ROOT, despite it being there in the registry and return false from the PdfRegistered function.
if PdfRegistered then
ShellExecute(0, nil, pchar(pdfFile), nil, nil, SW_SHOWNORMAL)
function TfrmMain.PdfRegistered: boolean;
with TRegistry.Create do
RootKey := HKEY_CLASSES_ROOT;
Result := OpenKey('.pdf', False); // False = do not create