In theory you can't, if it's in NTFS. But, if I'm not wrong, there was an Addon to manage NTFS disk (but I can't chek now because I now use only OBH 4.2).
But, even if you had formatted this HDD in ext3 or, better, ext4, you need also to mount it, before using it. Did you do both things?
And, each image is different: otherwise they wouldn't exist
Maybe some of them have also the NTFS driver already built-in.
I'm never been interested, though, because I rather have the VU+ HDD formatted in ext4 because is much more advanced than NTFS file format.