I have Windows 7 working on my laptop. I have 20GB space unpartitioned. I want to install a flavor of Linux like Fedora or Ubuntu in that space, but I have heard that keeping a dual OS configuration sometimes results in losing data stored on the hard disk. I've also heard that it may sometimes cause unrecoverable problem because when Linux is loaded on hard disk it will take over the boot loader from Windows.
Is this correct?
Moreover, I have 6 partitions in Windows, but if I use a Live CD for Ubuntu or Fedora to boot, then it is not showing some partitions -- sometimes it shows only 4 or 5 partitions. What might be the problem, and how to resolve it without formatting the whole hard disk and repartitioning it?