For me, the Windows folder & C drive totaled at 10.5 GB. Installed Windows Pro English after deleting all partitions in setup. Using 128GD SSD, i5 2500K, Z68 mobo, 8GB RAM.
It depends on your system. They have a new compression thing that works in certain situations. I think it mostly turns on if you have a small system drive and a fast processor, but I could be mistaken. You can turn it on manually via compact /compactos:always I think. But be warned that it will slow down file access a little bit.
Looks like Windows didn't compact my OS. Now the windows folder has grown to like 14 GB after updates and stuff.
I just installed an Windows 10 Enterprise LTSB 32bit on an Dinosaur Machine and the whole install was taken 8GB!! Just 50% of an normal install!!
I haven't upgraded my Desktop yet, just it will be more than 300 GB after done that! At the moment the C: HDD has 295GB already!!
@naseap, only efa11 has the authoritative monopoly on mdl for avatars like the 1 you have right now...just kidding