Is it correct that your most recent install is via torrent(s), or was it from official source?
Official source has it just under 7gb; unless someone repacked it (?), torrent shouldn't offer you any bonuses.

What you describe is either missing/corrupt data or in other cases would be driver related. If you have tried several GPU drivers and still have the same problem, it could be Windows 8.
What about compatibility mode for Windows 7, or do you have a copy of another Windows version you can install to test on?