This is from dictation.I can give you a longer answer by using my speech to text program. Otherwise I make a off a lot of spelling errors because of my handicapped.
By the way; speaking of handicap you can get a copy of Windows 10 upgrade from Windows 7 if you are handicapped person that needs the accessibility features found in Windows 10. That provision is still available from Microsoft.
Now back to topic. As you can see from the Wikipedia article there are a number of different tools used for doing a multi-boat thing. Of the different tools you can get, one outstanding tool is called eEasy BCD. It is a commercial product that you can buy or you can use it for personal use for free. It can help quite a bit with figuring out how to adjust the Windows boot loader options. It is capable of booting both Windows and Linux using the standards that conform to Windows. However, it does not have as much power as the boot loader used in Linux.
https://neosmart.net/EasyBCD/The best boot loader in Linux is the newest version of the GRUB boot loader. It is a free product and offers a great number of options, in fact it has too many options for most people even comprehend what it does. If it was possible to boot cricket Peter from a wet piece of spaghetti, GRUB would do it. It has all kinds of options that could hardly even imagine.
https://en.wikipedia.org/wiki/GNU_GRUBBut you may prefer to use the Easy BCD program. Another free tool I have found useful is called n
it is called macriumreflect.
Here is the link:
https://www.macrium.com/reflectfreeThe principal use of that program is to make backups of your hard drive by either cloning or imaging the drive. But it also has the special feature working can fix problems you have with the boot loader. I have used it a few times to help me with the problem with the boot loader. But I must admit it does have some limitations as to what you can do with it.
Presently I am only using Windows to triple boot between Windows 10, Windows 7 and Windows XP. Matter of fact, I'm using Windows 7 right now to do my dictation because the dictation program is a commercial product that does not allow me to use it on several computers at once or on multiple instances on the same computer. So I only use it in Windows 7. Maybe someday all thinks that, but I'm not in a hurry.
Whenever I want to boot Linux I use a CD to bring up a version of Linux that I'm comfortable with. Often do that when I have trouble booting my computer I can fix it with Linux. I know that sounds strange, but Linux has a tool called GPARD that allows me to do some things with the hard drive that are hard to do in other programs. Specifically, it can guarantee there is an MBR that can be used by the Microsoft boot loader.
Another thing that needs to inventions is the fact that newer computers use a firmware that does not conform to the older standards used in personal computers. Specifically, the newer computers require a secure boot option to load up a operating system. Now you can defeat that, but is not always clear how that is done. It is a security feature and they don't really want everyone to know how easy it is to defeat that security feature, so that I can hard for people to figure it out. Of course, that the is and crooks will figure it out anyway. Somewhere inside of the BIOS firmware there is an option for turning off the secure boot feature. If you don't do that, some boot loaders cannot work at all because they don't conform to the new standard for secure boot. I guess you've already found that somewhere.
Here is the method I used for doing triple boot on my system. First thing I did was to make sure the hard drive I wonder to use was in good shape. So I would run diagnostics on it by using some type of an external enclosure or else hang the drive on the end of a USB adapter that allowed me to control the drive through the USB port. Anyway, I would format the whole drive and check it for errors make sure it was a usable drive.
And after that the next step was to install windows XP from my CD and use my product key to make it a legal installation. After that, I would install Windows 7 on another partition and again use a product key to authenticate my installation.
After that was all taken care of, I would make sure there's enough room on the hard drive install another operating system. That means I would use some type of the disk partition software to move and create partitions. The one I most often use is called EASUS partition manager. It also is a product that you can use for personal use without the need to buy.
The last thing I would install would be Windows 10. This is a general rule for installing three versions of Windows. You start on a clean drive with the oldest version of Windows and then install the next version. I don't know what the limit is on how many operating systems you can put on one hard drive. You can even duplicate an operating system that you want and that is something I have done what I'm making test on something. At one time I had to copies of Windows XP on a system along with Windows 7 and Windows 10. At the time there are some can a problem I was having with XP and apparently I did solve the problem and now I forgot why I did it.
Anyhow, the basic recipe for a triple boot Windows system is to start with a clean drive and then install the oldest system first. That works for me.
Now the more difficult thing is try to recover old programs and data that you have on an existing drive. I never have been very successful about copying programs over unless they are that type of program. There are some programs that are called portable programs because they do not require a real installation. These are the kind of programs you can put on a USB drive and pull it out of one Windows computer and go plug into another Windows computer and it'll run just fine. One of these is Thunderbird portable, which I use for my email. That way I can check my email whether I'm inside of Windows 7 or Windows 10. Unfortunately, support for Windows XP has dried up and there are a few programs that will still run with Windows XP unless they are themselves very old programs. You'll find that many companies now have stopped supporting XP and you have find out programs are available in the archives that will work on XP.
Another program that will work easily on different Windows versions is called Libre Office. It is compatible with all versions of Windows and it even has a portable version if you want to put it on a USB stick.
Another thing you need to watch out for when using very old computers is the limits on drive size. This can be very confusing, because the computer will not speak up and say 'hey, that drive is too big for me.' Instead, you find out when you get everything installed and then things start messing up. It is a very bad experience to find out the firmware in your computer does not support the large hard drives now available. It can ruin your life.
https://www.linuxquestions.org/questions/linux-general-1/what-exactly-is-lba48-174457/I have been using multiboot four years, mostly because I am such a slow learner that I'm just now catching up and figuring out how Windows 10 works. I spent in an ordinance amount of time learning how to diagnose and fix Windows XP on to find that I had to switch over to Windows 7 and then after that I had to switch over to Windows 10. Hopefully, Microsoft is going to stick with Windows 10 for a while. So they say.
By the way, another boot option is to have two separate hard drives on your computer. Almost all desktops have provision for a second try, but that's hard to do on a laptop computer unless the second drive is a solid-state device.
Of course, the second boot option has to be set up inside the firmware, that is the BIOS.
Okay, I think that's enough for today. Maybe this will be of some help to you
