When I download Mathcad 14, the download fails just before it is complete. Can that be fixed or can I unload the program from a different source?
That is VERY old!
MathCad 15 was released in 2010.
What language are you trying to download?
I doubt there is any other legal source to download the software from.
Do you have licenses to run a new version?
You should be able to download the M020 release from here:
I downloaded the english and german version with little problem.
Restore your license by contacting via "Mathcad Support Center": https://support.ptc.com/support/mathcad_supportCenter.htm