Because AutoCAD 2004 was the major software on the market throughout 2003, it is frequently misidentified as "AutoCAD 2003". What is a "Portable" Version? History of AutoCAD versions - CAD Forums
A "Portable" version of any software is a modified executable that runs directly from a USB flash drive, external hard drive, or a folder on your hard drive without requiring formal installation into the Windows Registry. A truly portable AutoCAD 2003 would: