I just stumbled upon this problem on my Windows10 machine, ie where PICMultiCalc wouldn't run due to missing MSSTDFMT.DLL
It's very strange because I've had this machine up and running for several months and can't Believe I've not had to use PICMultiCalc on all this time. Anyway, the fix is as above but it took some additional steps to get it to work on my machine.

* I had to start Windows10 in fail safe mode in order to be able to actually copy MSSTDFMT.DLL to the SysWoW64 folder.
* Run the command prompt as Administrator
* Exectute the command %systemroot%\SysWow64\regsvr32 c:\Windows\syswow64\msstdfmt.dll

This succesfully registred MSSTDFMT.DLL and PICMultiCalc works again.

/Henrik.