I have been told by PTC advisor that Mathcad 14 is not compatible with Windows 8.1.
So I downloaded Mathcad 15 and found that would not intall either.
I have installed Mathcad Prime but without 15 Prime is not fully functional.
It seems I will have to abandon Mathcad and use other maths programmes - unless anyone has any ideas ?
Mathcad 14 may not be supported with Windows 8.1, but that doesn't mean it's incompatible. I have Mathcad 14 installed on Windows 10.
Clarify what issues you're having, and maybe someone can help.
The latest version of Mathcad 15 M045 and Mathcad Prime 3.1 release absolutely normally work for me in Windows 8.1 64-bit.
What happens when you try to install Mathcad 15?
And what happens if you install Mathcad 14?
Note that for each version some important prerequisites exist. Notably this concerns correct versions of .NET and MSXML. But once that's in order virtually ANY version of Mathcad will install on any version of windows since windows 98. Whether they will subsequently actually run (and especially 'run flawlessly') is a slightly different matter; but even in that respect, Mathcad 11 and all versions upward run without problems on windows XP and upwards, even 10!.