Windows 10: Dual Boot Win7/Win10 BSOD to Win10 UEFI partition, Win10UEFI USB, Win10UEFI DVD

I have a dual boot Win10/Win7 GPT SSD. I installed Win7 first, used shrink volume to create a partition and installed Win10.It has worked great and gives me an option which OS to boot into.Recently I have done something to create a BSOD kmode exception not handled going into Win10. Win7 boots fine.It will get the same BSOD, using an F8 when Win10 is selected, trying to go into safe mode or any other Windows RE attempt. I then tried my confirmed UEFI USB Win10 installer and get the same BSOD. I Tried booting to a UEFI DVD and also the same BSOD. The BSOD occurs after about 2 seconds of the sp

:)

 

How to dual boot win7 and win10

You need to install Win10 on its own partition.

 

Win7 / Win10 dual boot only boots to Win10

I have a home build machine with a dual partition for booting either Win7 or Win10 selectable.

The order was Win7 followed by Win10 in the menu.

The machine would always display a screen where I could select either Win7 or Win 10. If I didn't select in time the default was the first in the menu which was Win7

Starting this evening the machine no longer displays the selection menu but instead boots immediately and directly to Win10.

What's wrong?

How can I fix this so it works the original way?

 

Is it safe to increase the size of my System Reserved partition in a Win7/Win10 dual boot?

I have Windows 7 and Windows 10 in a dual-boot state (Win10 installed after Win7, both on different drives); but my Win7 installation does not create a separate
System Reserved partition. I assume that all Win10 files which are stored in a
System Reserved partition are stored in the System Reserved partition created by Win7...

...But there is one problem: As a stand-alone OS, Win10 creates a 500MB
System Reserved partition, and my Win7 System Reserved partition is only 100MB, and my dual-boot Win10 installation is using or sharing the Win7
System Reserved partition, since it was created first.

Here's the dual-boot screen:





Here's the dual-boot setup in Win10:





And here is the dual-boot setup in Win7:





Given a test run, I discovered that, with Win7 and Win10 on your machine, you can't have 2 separate
System Reserved partitions (one on the Win7 drive and one on the Win10 drive), because upon boot of one OS or the other, errors, blue screens and the need to repeatedly check the disks for consistency have the potential to corrupt either one OS or
both.

Since my assumption is that the Win7/Win10 dual-boot setup shares the same
System Reserved partition, is it safe to increase the size of this partition to 600MB (100MB for Win7 + 500MB for Win10), especially with the possibility that Win10 may dump enough files into this partition to completely fill or overwhelm the original
100MB that was created with the Win7 installation? I have Acronis Disk Director 12, which can resize any volume, before or after the OS partition.