Well, I did not have that folder as I usually clean up system files after a new install (have the old one as an Image anyway).
I went berserk today and deleted the whole partition of my DEV channel and reinstalled it from the newly released ISO and now it has a size of about 20GB again.....
The massive files download was actually in the folder " C:\Windows\Software Distribution\Downloads ".
I think something had screwed up the update thingamajob....
one more thing: After installing my computer is running like molasses. I have a suspicion that this pc will not get farther than the 2009...
the 20197 was running fine, the 20201 is like molasses.