How to install windows 7, windows 10, ubuntu 14.04 on one hard drive?

Question

Windows

I want to install 3 operating systems at once on a laptop, with the ability to remove or reinstall any of the operating systems at any time. How can I do that?
As far as I understand, you need to install a third-party bootloader.
There was an idea:
1 step. Partition the disk into 5 partitions (the first partition is for the GRUB bootloader; 2-4 for all operating systems; and 5 just in case, for example, for data, music, video)
Step 2. Install on the first GRUB partition.
3 step. Install windows 7, windows 10, ubuntu 14.04.
4 step. Configure GRUB to run the desired OS.
The first and third steps I know how to do. But there is a problem with installing and configuring GRUB (
Dear experts! Tell me, please, is it possible to do this?
Am I thinking in the right direction? Or is there some other way?

Answer 1

configuring grub
Well, besides GRUB, there are other loaders .

Answer 2

1. Split the disk into 4 primary (primary) partitions: 1st under the hornbeam + the rest /boot from Linux, 2nd and 3rd under windows, 4th - under Linux + common partition (since there are 4 primary partitions, Windows loaders will immediately be on the same section as the OS).
2. We put windows in the 2nd and 3rd.
3. Change the 4th partition to an extended one and split it into partitions for Linux and everything else.
4. Install Linux.
5. Set up the hornbeam.