Running both the host software and the keygen as an administrator is critical to bypass permission blockages in the Windows registry.
If you need AutoCAD for a project, use a or a free alternative like:
Cloud-based CAD platforms that offer free tiers for hobbyists, makers, and non-commercial projects.
Xforce is a well-known group within the software cracking community that creates "keygens" (key generators). A keygen is a small program designed to generate valid product keys or activation codes for Autodesk products, including AutoCAD 2013.