How set up dual boot with two version of Windows 10

Then the OS and the System Reserved will all be under one lettered drive. Then, I won't have a C: partition (if I understand you correctly). Could you explain to me what I'm doing and why please? Exactly what is the System Reserved partition? I'm not getting the logic.

The system reserved partition is where the boot files are supposed to be. You assign the system reserved partition it's own drive letter, like R. Then you use EasyBCD to move the boot files to the newly created R: drive using the tutorial I linked.

Very sorry - but this tutorial is over my head and I need more help

I gave the System Reserved partition the letter "R" - the I got lost because I don't understand the terminology - or where to find what's referenced in the Tutorial.

Where do I find the BOOTMGR (what's it called in EasyBCD)
What is the selected partition (R or C?)
How do I install the bootloader?
What is the boot sector?
What is the MBR of the selected partition?
What is the old boot partition - R?
Update partition references (I assume I can now edit) - but what references do I change to work with the new partition.

Actually, I don't want you to explain every little thing to me as I like to do as much by myself as I can. It's the only way I learn more than I know now. However, in this instance, I'm over my head - even if I look up the terms I don't understand. I can't put the pieces together. I've been looking over EasyBCD and its' options - and the instructions in the link you gave me. I just haven't been able to perform the steps. The steps came from the link you sent me. I don't understand why you now say the questions are unnecessary. I'm stuck! I've been at my computer trying to understand what to do while waiting for a reply.

As for not seeing Windows 10 installed over Windows 7, I again don't know what you mean. When Windows 10 was first released, installing it on top of Windows 7 was one of the option to install it. It was like a repair install - only using Windows 10 instead of Windows 7. I don't know what you're looking for. I am using Windows 10 - but DM still calls it Windows 7. I don't know why. I can easily change the name of the OS in DM - but I can do that after I achieve what I'm trying to do. I want to get to the point where I can safely clean install Windows 10 in a new partition. But I won't purchase it until I'm ready. I don't have the cash to buy it only to let it sit here because my system's not ready. Also, I know to only disconnect the other drive - not physically pull it out of the computer. Perhaps I misworded something. All of this typing could be spared by doing this by phone and, if there's a misunderstanding, it can be corrected instantly. Now, I'm ready to learn - are you willing to teach me? BTW, I can only see that your Disk 0 has two partitions. I can't read anything - it's too small and blurred. You also said "The System Reserved partition and the Windows partition are 2 separate partitions, I always create an install partition for Windows so I don`t have a System Reserved partition, I don`t need one and I don`t want one." See, I wish I knew the answer as to why you said that. I want to learn and would like to know what you meant and why. Thanks for the help so far. Please keep it coming.............

Just went through everything again and looked up boot loader. But I'm still stuck on how to use the link to EasyBCD. Without the help (hand holding) I need on this one, I won't succeed unless I find another source to help me.

@Nisko,

Once you get EasyBCD installed there are only three steps:

Go to the BCD Backup/Repair tab. Select Change Boot Drive. In the drop down box next to New Boot Drive, select R. Click OK.