Since the 5.0 version is no longer sold or officially hosted for download, users typically use one of the following official paths to access the software:

Official PTC Mathcad 15 and Prime 1–6 End-of-Sale Announcement

If you are looking for a , it is important to know that PTC officially retired support and distribution for all versions prior to Prime 7.0 at the end of 2021. While you can no longer get the specific 5.0 installer directly from PTC, you can still access the core functionality of Mathcad for free through modern alternatives provided by the developer. Official Ways to Get Mathcad for Free