Why is Windows 10 copying files twice?
On Windows 7 when you did some file operation it did it once and it was done. But on 10 f.ex. WinRAR does it's progress bar and then there is this horribly slow progress bar from Explorer that takes more time than the actual unzipping.
What is going on?
I can speak for 7zip: if you drag&drop files from a 7zip window onto some windows explorer window, then, files will be unpacked to temp folder on C drive, then moved to their final destination. But, if you just mark all files you want unpacked and hit the Extract button in 7zip window, and then in the next step you choose destination path, the files will be unpacked straight to destination path, therefore making the whole operation twice as fast.
WinRar extracts all files into some system directory by default (I'm not sure is it possible to change), no matter of Windows version. If you have 10Gb free on system drive and you want to unpack 11Gb file you just can not do this. If you unpack the file somewhere into C:\ then second operation will be instant, otherwise it is going to be moved to other drive.