Where is my downloaded file?

I was downloading part of a video file. I had designated for it to be saved in my D: drive. Usually when I download a video/music file, it gets downloaded into another file and then gets “transferred” to my designated destination. The “temporary” file foldr usually looks something like this: 4FC67QT6. I cannot locate where this file is. My computer shut down before the video file was transferred to my D: drive.
I have tried to do a file search, I looked into the temporary internet file folder, but cannot find where this folder is located.

Does anyone know where such a “temporary” file would be kept. I am wondering if it is created temporarily and then disappears after my files get transferred to their designated destination.

Can anyone offer any help?
Thanks in advance!

What software did you use to download? Often the path to such files is set within that software, or at least shown in the configuration menu.