Using a pre-activated Enterprise edition from unofficial sources is highly discouraged due to the following risks:

If you need a legitimate copy of Windows 8.1 for testing or specific enterprise needs: Windows 8.1 AIO x64 Pre-Activated ISO - Scribd

While these versions are often found on file-sharing sites, they carry significant security risks and legal implications. What "Pre-Activated" Means

Modified ISOs frequently contain hidden malware, spyware, or "backdoors" that allow unauthorized remote access to your data.