Interesting to see that the HDD space requirements quoted in both the Windows 8 and Windows 7 articles is the same: 32-bit-16GB; 64-bit 20GB.
FWIW on my nearly 2-year old Windows 7 Pro system, the system partition is 200GB, the Windows folder is 22.8GB, 88,519 files, 18,730 folders. The Winsxs folder is 9.50GB, 53,306 files, 13,413 folders.
So perhaps 10% over the quoted space requirements, but the system is probably carrying a bit of overhead from add-ons I've installed. WinDirStat tells me the Installer folder is the 2nd largest after Winsxs at 4GB. I'm guessing that is for Windows updates and the like, don't know if any application stuff (whether MS or otherwise) goes in there.
Am I concerned? Certainly not. ~10% of the partition, ~2% of the actual HDD, for the system is negligible.
As a comparison, though perhaps not a very good one, how much of the volume of a car is taken up by the engine, transmission, steering and suspension, fuel tank? I suspect more than 10%.
[Edit to add age]
Tony
We have more and more laws, and less and less enforcement
Edited by cheshire_man (Sun 07-Apr-13 22:46:50)