Downloading “full” versions from torrent sites, file-sharing forums, or unknown blogs often leads to:
If you are looking for an AutoCAD 2011 download because you need a lightweight, functional CAD tool, you might consider: autodesk autocad 2011 64bit download full
If you do not own a license:
If you are looking to obtain or install this specific legacy version, here is the current landscape: Official Status and Support Retired Product Downloading “full” versions from torrent sites
: Offers a free version that feels very similar to the classic AutoCAD interface. functional CAD tool