Windows 7 to 10 upgrade on a tablet where does it save the Windows 10

I have a tablet with only 4.08GB space on C:

My question is where does it keep downloaded windows 10 files?

Idea appreciated

I do have a SD card of 64GB and plaing on installing Program Files there but nothing installed right now so they are taking only 200MB

and Windows folder itself is 9GB

also wondering if it's possible to tell the downloader to use alteative location instead of C: