When downloading the ISO, you must choose between two architectures:
Before proceeding, ensure your hardware meets these minimum requirements:
Before downloading a Windows 8.1 ISO, ensure your target machine or virtual environment meets the minimum hardware specifications: Minimum Requirement Recommended 1 GHz or faster with support for PAE, NX, and SSE2 2 GHz Dual-Core or faster RAM 1 GB (32-bit) or 2 GB (64-bit) 4 GB or higher Hard Disk Space 16 GB (32-bit) or 20 GB (64-bit) 40 GB or higher (SSD preferred) Graphics Card Microsoft DirectX 9 graphics device with WDDM driver DirectX 10 or higher Display Resolution 820 x 600 pixels 1366 x 768 pixels or higher Where and How to Download a Windows 8.1 ISO Safely windows 8.1 iso
Avoid third-party torrents or "Windows 8.1 ISO download" sites. Many of these files contain malware, rootkits, or modified code that can steal your data. Always download directly from Microsoft.
Splitting large install.wim (if needed): When downloading the ISO, you must choose between
A USB flash drive with at least of capacity. Note that all data on this drive will be erased.
Select if you are installing on an older computer with a traditional Legacy BIOS. Splitting large install
When using third-party sources, always verify the SHA-1 or MD5 hash values against original Microsoft documentation to ensure the file has not been injected with malware. Official Windows 8.1 ISO Editions
A USB flash drive with at least 8 GB of storage (all data on this drive will be erased).
If your hardware supports Windows 10 (it likely does), Microsoft still offers a free upgrade path. You can clean install Windows 10 using your Windows 8.1 key.