AutoCAD 2012 was designed before the widespread shift to Windows 10 and 11. A genuine 64-bit version requires:
Which option would you like?
Fusion 360 (free for hobbyists and startups under certain revenue limits) is cloud-based and installs quickly, but it is not strictly portable. However, it runs well on modest hardware and saves everything to the cloud, so you can access your work from any machine after a short install. autocad portable 2012 64 link