A: No. Autodesk never released a free version. Any "pre-activated" portable is pirated.
A: Consider QCAD (open source, 2D only) or LibreCAD . Both have true portable versions for 64-bit systems and save to .dxf . autocad 2010 portable 64 bits ingles
Have you successfully used a portable AutoCAD 2010 64-bit? Share your experience in the comments below, but remember to scan every file with VirusTotal first. a standard install would work better.
A: Possibly, but not officially. You would need to install the old .NET 3.5 and VC++ 2008 runtimes. A portable version adds more complexity; a standard install would work better. autocad 2010 portable 64 bits ingles