I have a dual boot notebook (using GRUB): Windows 10.0 & Linux ubuntu 14.04 which has been installed after that. I want to purge Windows 10.0 and perform a completely clean Windows 7.0 installation including some minor changes to Windows partitions. Actually, I took the free offer from Microsoft to auto-upgrade from 7.0 to 10.0 but after doing so, my notebook performs too slow and very poor. So I want to get back to 7.0. The problem is that Windows 7 setup programme says that if I want to do anything related to the partitions, I've got to boot from Windows DVD and from there I'b be able to perform installation from zero but:
- Whenever I want to boot from DVD, a message appears saying that boot from CD/DVD is blocked (or forbidden) somehow.
- Also, I am kind of worried about booting from DVD and trying to purge that Windows: Damaging GRUB or corrupting Linux or something like that.