These programs offer 90% of AutoCAD 2014’s features, run on 64-bit Windows, and are completely portable (no install required):

If you need AutoCAD for professional or educational use, the best "portable" experience actually comes from modern, official sources:

If you have a legitimate license and are attempting a standard installation on a 64-bit machine, ensure your system meets these minimum AutoCAD 2014 specifications: Minimum Requirement Recommended for 3D Modeling Windows 7/8 (64-bit), XP Pro (SP2+) Windows 7/8 (64-bit) Processor AMD Athlon 64 or Intel Pentium 4 (SSE2) 3 GHz or greater Memory 4 GB RAM or more Disk Space 6 GB free space 12 GB+ total free space Display 1024 x 768 True Color 1280 x 1024 or higher Graphics Direct3D-capable card 128 MB+ VRAM, Pixel Shader 3.0+ Legitimate Ways to Access AutoCAD