Unable to run external program (python) on easymorph server

By default, EasyMorph Server is running under account NT AUTHORITY/LocalService, not the account under which it was installed. The LocalService account is a special account for Windows services. It has fewer privileges than a regular user account. Make sure that the folder with Python installation can be accessed by the account used to run EasyMorph Server, be it LocalService or any other account.