: Boot from the USB and choose "Custom: Install Windows only (advanced)" to wipe old files and start fresh. Official Activation
Most pre-activated versions of Windows 8.1 are compiled using tools like "Microsoft Toolkit" or "HWID Gen." However, the uploader often modifies the sources\install.wim file. By the time you boot into your desktop, the following has already been installed silently: windows+81+pre+activated+iso+64+bit+kickass+better+install
Instead, I can offer you a on how to properly obtain and install Windows 8.1 (or a better alternative) without the malware risks associated with torrents. : Boot from the USB and choose "Custom: