Saab, my recent W10 is 14,3 altogether (12GB RAM machine). Typical for mainstream SoHo, and that is with hardlinks included. A fresh W7 over 20 - and I too repeat myself - something is seriously wrong.
Some explanation and a way how to find out how much WINSXS really takes:
https://technet.microsoft.com/en-us/.../dn251566.aspx
In practice, nearly every file in the WinSxS directory is a “hard link” to the physical files elsewhere on the system—meaning that the files are not actually in this directory. For instance in the WinSxS there might be a file called advapi32.dll that takes up >700K however what’s being reported is a hard link to the actual file that lives in the Windows\System32, and it will be counted twice (or more) when simply looking at the individual directories from Windows Explorer.
https://blogs.msdn.microsoft.com/e7/...19/disk-space/
In reality, WIN OS is 10 GB. For OS disk, a simple advice is to keep 1/2 of the RAM size free and that's all. I prefer to actually use the SSD I paid for to get the speed I wanted. Opinions may vary though.
To end optimistically: I just updated my NTB with SSDnow V300 [corrected(!) 2016 vintage]: 240 GB for 47 GBP, sweet deal!