To ensure your PC stays safe and you get a working version of the game, consider these official retailers:
A reliable digital storefront for safe PC game downloads .
Offers the Complete Edition which includes all six DLC packs.
Users have reported that these sites often contain heavy adware and may prompt you to disable antivirus software, which can lead to installing trojans or other malware.
If you're having trouble with specific file parts, this guide can help clarify the download process for this title: