You can convert legacy Mathcad files (.mcd) to Mathcad Prime 2.0 MCDX format using the original software, no 3rd party software required.
When you convert a legacy file to Mathcad Prime 2.0 format, the converter annotates all unsupported content and saves the original content as an image. Annotations are also used to flag differences in calculation methods, result formatting, or operator display.