It's a localization error. /r recurses on all subdirectories, and /d y (y for yes) bypasses the prompt to act on each subdir. My guess that you'd want to use /d s (for sì). Alternatively, you can leave out the /d y, and just confirm for each subdir.
To get parameter description for takeown or any command, enter at the prompt command /? > C:\command.txt, so for takeown, enter takeown /? > C:\takeown.txt. Then peruse the text file with Notepad.
If you have limited space want to minimize Win8 footprint, there are more substantive means to do so. One is to manually set a smaller pagefile with a WMIC command (subject to localization differences):
Set pagefile: wmic pagefileset where name="C:\\pagefile.sys" set initialsize=1024,maximumsize=1024
Check pagefile: wmic pagefileset
Reboot for it to take effect. The above sets pagefile to a fixed 1GB size; you can adjust to taste. You can of course adjust it via the usual GUI route.
Second is to reduce or remove the hibernate file. For a desktop, where power isn't an issue and you don't reboot often, my suggestion is to disable hibernate. When hib is disabled, fast boot is off, and booting will take slightly longer.
Disable hibernate: powercfg -h off
For laptops, you can reduce hibernate file size by up to 50%.
Set hibernate size to 50% of RAM (50% = min): powercfg -h -size 50
Personally, I also removed all the "reserved" partitions, and handle my own backup/restore with 3rd-party tools. For a tablet with SSD, this can recoup substantial space. But it's more involved, and best done during a fresh install.