Installation, data packs

I've tried downloading this client from different sites. (Cnet, Filefront, Direct Download)

Whenever I finally finish the download, which takes an average of about 8 hours each, I get a diagnostic error with WinRAR saying that the data pack is corrupt or broken.

I tried Direct Download and when I'm extracting data pack 1, it says
Read error in the file C:\Documents and settings\Name\My Documents\Downloads\PWI_v166_XP.part1.exe

I tried the bittorrent with Utorrent, but it stops early in the process with a cyclic redundancy check.

I've downloaded this game before with problems, but its usually solved by downloading the client over and over again, this time, I'm having to download more than usual.

I'm wondering if this is a problem with my computer, something during the download process, or something else.

Question is, what possible problems might cause all of this and what steps can I do to fix it?

Btw, I've looked over the forums for days and there are no solutions I've seen so far.