Windows 10/7 dualboot not working after Creators Update

I've got an interesting problem. I dualboot windows 10 and windows 7 on 2 separate drives. Since the Creators Update (which i got around to doing yesterday) windows 7 refuses to boot with the error code 0xc000000e (The boot selection failed because a required device is inaccessible.)

I did everything i could think of, such as getting my win7 install disk and running 'bcdedit \fixmbr', 'bcdedit \fixboot' etc etc to no avail. I also tried to do this with a windows 10 installation USB as well, which managed to fix my windows 10 partition to be bootable, which is what i'm on at the moment. The BCD store also seems to be correct, and the output is here :

C:\Windows\system32>bcdedit

Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=\Device\HarddiskVolume7
path                    \EFI\Microsoft\Boot\bootmgfw.efi
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
default                 {current}
resumeobject            {162f26ca-81fe-11e7-932b-0015834866b0}
displayorder            {current}
                        {b5a51eaf-81b1-11e7-9a5d-ec99282cf732}
toolsdisplayorder       {memdiag}
timeout                 3

Windows Boot Loader
-------------------
identifier              {current}
device                  partition=C:
path                    \Windows\system32\winload.efi
description             Windows 10
locale                  en-US
inherit                 {bootloadersettings}
isolatedcontext         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=C:
systemroot              \Windows
resumeobject            {162f26ca-81fe-11e7-932b-0015834866b0}
nx                      OptIn
bootmenupolicy          Legacy

Windows Boot Loader
-------------------
identifier              {b5a51eaf-81b1-11e7-9a5d-ec99282cf732}
device                  partition=E:
path                    \Windows\system32\winload.efi
description             Windows 7 Ultimate
locale                  en-US
recoverysequence        {b5a51eb2-81b1-11e7-9a5d-ec99282cf732}
recoveryenabled         Yes
osdevice                partition=E:
systemroot              \Windows
resumeobject            {56a5fe76-81aa-11e7-93cc-806e6f6e6963}
bootmenupolicy          Legacy
bootlog                 Yes

C: is the current Windows 10 disk in this case, and E: is the Windows 7 disk.

The strange thing is that sometimes it boots when the windows 10 installation usb is plugged in, but sometimes it doesn't, and it seems to be completely random.

Forgot to add, if i remove the drive that has windows 10 on it, windows 7 boots perfectly fine.