Question I can't clone Windows (ONLY Windows, not data) from half-full 1TB HDD to 120GB SSD because the SSD isn't large enough.

[hang-the-9]

Have you tried to backup windows and programs, install windows on ssd and do a backup restore? I think there is option to backup only windows and programs

That is very likely to be well over the 120 gb size of the drive. The core of the issue is that the SSD is too small.