copying protected Word file results in an XML file, what to do?

I do backups and have this one file, very important that is protected in Word with a password.  I didn't look at my backups, till now when my computer failed.  I have multiple copies of this file and I have the protection password onhand.  So I should be easy to get the file back, but something strange happened.

The file was like this originally:   mydoc.docx  (it is protected with password)

The copy of the file on the backup drive looks like this:  mydoc.xml  (I assume it is the same file(?) because every time I backed it up it came out like this with the XML suffix instead of the docx  suffix.

I have no idea how to use this file now since it's not a docx file.  Do I open in Word and try to resave it as something?  Or what?  I see some things about how to crack files using XML, etc, but I don't need to crack the file, since I do have the password.  

any help greatly appreciated.  Bob Luhrs