New PCs (including ASUS Eee Boxes) come without recovery medium, but they seem to have a recovery partition on their hard disk. You have to find a utility, that copies that hidden partition to an external bootable medium like a USB memory stick (that needs to be bootable!!!).
I used R-Drive Image for that. Its evaluation period was long enough for my purpose.
This article by Benny Neugebauer didn’t actually describe my problem, but it helped finding that utility.