"Preactivated" ISOs from third-party sites often contain malware or backdoors. Always scan the ISO with updated antivirus software before use.
Windows Server 2008 R2 Preactivated (July 2013) 64-Bit Installation Guide
Installing this specific x64 build follows the standard Windows NT 6.1 setup procedure: 1. Requirements
Choose the edition (Standard, Enterprise, or Datacenter). Note: Standard is usually sufficient for most file-sharing and active directory tasks. Select installation to format your drive. The system will expand files and restart several times. 4. Post-Installation and Activation
It is vulnerable to numerous exploits (like BlueKeep or EternalBlue) that were discovered after 2013.