Error: "prefix" not set

[Mossmyr]

Tried installing kubuntu with WUBI, and when I rebooted the computer I got this error:

Try hd(0,0) NTFS: No wubldr
Try hd(0,1) NTFS: error "prefix" not set.

I've reinstalled it 3 times (formatting the hdd every time) with same results.
Installing Ubuntu with wubi works fine, but not kubuntu.

Same problem as this guy :/