You have to have one of these:
Mirror 1: EpicPW Descent client
Mirror 2: EpicPW Descent client
And you need to unpack one of them by this PARTIAL download:
Partial download (7-zip is required to unpack the client):
EpicPW - part 1
EpicPW - part 2
EpicPW - part 3
EpicPW - part 4
EpicPW - part 5
EpicPW - part 6
EpicPW - part 7
EpicPW - part 8
Is what I mean.
'7-zip is required to unpack the client' meaning to uncompress the client (one of the mirrors)
From what you've said I may be wrong but you're just downloading the 8 parts, unless you're downloading this from somewhere I do not know of...