This remains the only 100% official and safe source provided by Microsoft. If you have an active developer subscription, you can log in at my.visualstudio.com to download verified Windows 8.1 Pro ISOs with official SHA-1 hashes.
Before you start downloading Windows 8.1 Pro, ensure that your computer meets the minimum system requirements: microsoft windows 8.1 pro download
The popular Rufus utility has historically allowed users to download Windows ISOs directly through its interface by selecting the "Download" option instead of "Select." This tool fetches files from various Microsoft-associated scripts, though its reliability for older versions like 8.1 can vary. This remains the only 100% official and safe