SOLVED... How can I install another operating system?

[jorava]

Hi guys, I have two partitions, the main one is Linux Mint 18.1 and in the other partition I have Windows 8.1. It always shows at the beginning the grub shows the two systems, now I want to format the Windows 8.1 partition and put Windows 7. How can I do this? How can I reset the grub? thanks for any idea.

[jimallyn]

It is generally easiest to have Windows installed first and then install Linux. However, I have heard several people say that if you just format a partition NTFS, the installer will find it. I have never tried that myself, though. (I assume that means an empty NTFS partition.)

Depending upon what you need or want Windows for, your best bet might be to install it in VirtualBox. Then it's always right there in Linux, and you don't have to reboot to get to it. VirtualBox works well for most stuff, but serious gamers will find it a joke and will definitely dual boot.

[AndyMH]

Backup first!!

Download a copy of boot-repair. When you install win7 it is likely to bork grub, hence when finished on a reboot you are likely just to get windows. Use boot-repair to fix it:

https://sourceforge.net/p/boot-repair/home/Home/

[hcentaur13]

When you run a partition table of typ GPT and UEFI it doesn't matter which OS you installs. Else windows will destroy the bootmanager because it thinks it is the only OS that exists. It will destroy the MBR. No problem at all. Use supergrub to boot linux and let it install grub again.

When you use UEFI to boot you can install whatever you likes at least. Because UEFI comes with it own boot partition that allows to select which operatiuon system should boot now.

[jorava]

Thank you very much guys, thank you very much Andy, it helped me a lot to use boot-repair, I recovered the grub after formatting my windows partition again. Blessings to you.

[AndyMH]

Been there done it (or very similar)