Community Tip - When posting, your subject should be specific and summarize your question. Here are some additional tips on asking a great question. X
There is absolutely no way via PTC support to reactivate a licensed Mathcad version below 14 for any reason. Essentially, the program is hijacked for upgrading to a newer version.
Maybe this helps: Re: Mathcad 11
Support for 11 ended for sure, don't remember if that's also true for 13.
Success!
Luc
It's true for 13 and below. I'm not sure about 14. If Mathcad 13 is on the same PC then the license file should still be valid though, so it should just be a case of pointing Mathcad to the license file.