Here is everything you need to know before you click that download button. In theory, a "portable" app runs from a USB stick without installation. A "REPACK" usually means the software has been compressed, cracked, or modified to bypass licensing.
But let’s cut to the chase:
Uninstall any "Civil 3D 2015 Portable" you have downloaded and run a full antivirus scan immediately. Then, sign up for an Autodesk Educational License or subscribe to the AEC Collection for the latest stable version. Have you been burned by a fake portable software download? Tell us about it in the comments below. Download Civil 3D 2015 Portable 64 Bit REPACK