Programs enabling conversion of the file:
If your objective is to convert the file from VHD to the file OVA, you can use any of the applications listed. VHD to OVA conversion process in every program intended for this purpose (so-called converters) is very intuitive and everyone is able to manage converting a file.
However, bear in mind that the list may also include programs to support and work with the indicated extensions VHD and OVA - and not only converters. In such a case, you need to open the source file VHD and from the options available in the program, choose ”Save as... OVA" or "Export to OVA".