Corelcad Portable
There are completely free, open-source design programs available online. Tools like LibreCAD or FreeCAD cost nothing and are safe to download.
Benefits of portable software include:
CorelCAD Portable bridges the gap between intense, professional design requirements and the need for modern, mobile work environments. By allowing engineers and designers to run a full-featured CAD suite from a USB drive, it offers the freedom to work whenever and wherever inspiration strikes. corelcad portable