Please help me with my external HDD problem , i am begging you!

Hello , i have an external HDD that was an NTFS volume, and was full of data , i tried to use it to instal windows 8.1 from it, when trying to boot from it, it prompted endless os to install, i didn t know what this is, i have never seen it so i closed it. When i tried to enter my external hdd , it can not be seen , it has been modified, i can not acces it. I use and hdd with adata XPG, and i think the hdd is from an asus laptop.
Did i loose all of my files can i get them back , please help me, i had my life s photos on that drive

If booting your external HDD shows you an installer for Endless OS, it sounds like you (or somebody using your computer) may have set up an Endless install USB on your external HDD. We can see what’s on the disk and try and find what’s happened by first examining the partition table. Which OS is running on your computer now?

If it’s Endless OS, please search for “Disks” on the desktop, and find your external HDD in the list on the side. Select it so that it shows the partitions on the right hand side, and then take a screenshot (hit Print Scrn button) or photo with a phone and attach it.

If you have Windows running on your PC now, you can do the same thing with the “Disk Management” tool, if you search on the Start Menu. Take a screenshot or photo to show us the partitions on your external HDD and attach it here.