As .asd files are just basically backup copies of unsaved Microsoft Word documents, you might be able to simply open them using Microsoft Word. Unless they are corrupted, there should be no problem, however you have to use a proper version of the program.
These files are not associated with Word by default, so you can also try to rename them o .docx, or manually browse to it through the File → Open function and select all files in the filter. If that does not work, then these files most likely corrupted.