System & reserved is eating 5.16GB of internal memory of my Lumia 640 LTE. it's os is Windows 10 1703
Can I clean this space up after unlocking the phone?
I also have an AT&T 640 that I unlocked that has the same memory used by the win 10 OS. Unlocking will not give you more usable space it seems. Just buy another memory card to solve your problem.