If you download the current version of the program  you will undoubtedly encounter bugs (some really severe, but most fairly benign).  You can minimize this by only using the full installs at the USNA site, but even these will have bugs from time to time, and the full install might not be updated very often.  

Update the program backs up the old EXE.

Hints to help manage multiple copies of  MICRODEM:

Last revision 10/12/2017