As of now, I have a single 500GB hard disk with Windows installed first on one partition and Ubuntu installed on another partition. Since Ubuntu was installed second, it detected the Windows partition and Grub provided a dual boot. Sometimes, after installing Ubuntu, the Windows drive-letter C changes to D and Windows does not boot.
Problem is, when I wanted to install a newer version of Windows, I installed it, and now the system directly boots into Windows. No option of booting into Linux is provided.
So two questions:
1. In a situation where I want to reinstall Windows or Linux with a newer version, how can I prevent the dual boot option from getting ignored?
2. Is there a way to make the Windows partition and Linux partition completely unaware of each other? Perhaps by having a third party bootloader, which can detect which operating systems are on the disk and allow me to choose which I want to boot into, and also allow me to completely remove/replace one of the operating systems with a new one, and still be able to boot into either that OS (Windows) or into Linux OS which was un-touched?