raf, yeah but if you have to go to the file explorer (which may not be open at the time) that means you have to boot up explorer, migrate to the folder the file is in and THEN double click. As to setting opera 27 as the default browser to open files like mht defeats my already default app of Opera 12.17, which I use MOST of the time...as Opera 27 has as yet not even come close to providing me with the kind of options I require for a browser (as in Opera 12.17). When I need Opera 27, I simply do a "Open With Opera" from within my 12.17.
The ctrl + O is actually the answer I was looking for, thanks.