Thanks for your appreciations, willjackson and maria! As maria says, there is a lot of software for data recovery and to get a clone of the HD. The need of it is so basic that they exist since the first days of computing. But the purpose of this tutorial is not exactly that: 1.- It tries to configure your HD in the optimal way to keep safe and apart your personal files, while "repeating" your Windows 7 into two primary units of the same disk which are also optimized just for this OS. 2.- The purpose of this tutorial is just to take profit of the grub-mode facility which appears under Windows 7 to have two copies of your OS totally operative into two different primary partitions of the same HD, choosing at boot one or the other. AFAIK ordinary clones from Windows 7 can only be used to rebuild the original drive. 3.- When your Windows 7 freezes or stops working for any motive you feel really happy if you can switch inmediately to an exact copy of the same software, shortcuts and apps, not only to go on working without delay in the same usual way but also to delete the damaged drive unit and rebuild it from scratch on the background from a logical unit, external HD or DVD in less than 15 minutes. No problem of drivers and no need to remember but a single install scheme. 4.- The saved clone is totally transparent: it allows you to examine at any moment any of the elements of the OS, even the hidden ones (preferably using Total Commander in this case). This option is very useful in many occasions.