I have a Sony VAIO PCV-RZ424 with Windows Home Edition pre-installed (acquired new 7 years ago and still going strong). I have just been given an external hard drive but this does not come with back-up software and I can't find the facility on my PC. Presumably the back-up was not included in the initial installation and I do not have the system disk. Can anyone please point me to the way to install it now?