I am also having problems with Reader 8.1 and Vista home premium on a new laptop. It won't open some pdfs and states that 'it is either not a supported file type or because the file has been damaged (eg it was sent as an email attachement and wasn't correctly decoded)'. I wasn't given Vista on dvd with the laptop so can't reinstall. Is there something I can do to sort it out please? This is also happening on PC with Reader 7.0 and Vista. Thanks.