The win7 mentioned is latest since it is auto-updated. win10 is version 1903.

This is not the first time I am doing this. Months ago I did it on my own PC: old system is win7 with single HDD, I shrink the win7 partition to spare new volume for win10, install win10 with USB media, and I automatically got dual boot after finishing, and using both so far so good. Yesterday I did the same for my friend on his 7-year old laptop (lanovo x230) which is also a win7 on single HDD system. At first, everything went as expected. After it went through the setup with green checks up to FInishing Up, it rebooted and I could see dual boot of win 10 and win7 there. Naturally, I selected win10 for it to continue the installing, then it went through the initial setup, creating first user etc., it reboot again. But this time not dual boot appeared. It went straight into win10. Now I am not able to boot win7 thought win10 seems to work fine.

Searching the web for solution but all are telling me the same method I did above. None so far on how to create dual boot when you have both OS in place but no dual boot. I did a
Code:
bcdedit
on win 10 and attached below. Hope somebody can tell me what to do next. Thanks in advance.

Code:
Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=\Device\HarddiskVolume1
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
default                 {current}
resumeobject            {------------------------------------}
displayorder            {current}
                        {------------------------------------}
toolsdisplayorder       {memdiag}
timeout                 0
Windows Boot Loader
-------------------
identifier              {current}
device                  partition=C:
path                    \Windows\system32\winload.exe
description             Windows 10
locale                  en-US
inherit                 {bootloadersettings}
recoverysequence        {------------------------------------}
displaymessageoverride  Recovery
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=C:
systemroot              \Windows
resumeobject            {------------------------------------}
nx                      OptIn
bootmenupolicy          Standard
Windows Boot Loader
-------------------
identifier              {------------------------------------}
device                  partition=E:
path                    \Windows\system32\winload.exe
description             Windows 7
locale                  en-US
inherit                 {bootloadersettings}
recoverysequence        {------------------------------------}
recoveryenabled         Yes
osdevice                partition=E:
systemroot              \Windows
resumeobject            {------------------------------------}
nx                      OptIn