Have you tried to just change the file type from xyz.txt to xyz.pgn ?
Open the file with wordpad or whichever text editor you use, then save it as a pgn file. That should create a new file and also preserve the original as a txt file.
Or you can just copy the original file to a new folder and then change the copied filename without even opening it. (that will also preserve your original .txt file.) Right-click the filename and then just change the 'txt' to 'pgn' and save it. It should open after that as a pgn file.
A kipper sandwich is great. No seasoning or condiment needed. Just the kippers on some plain bread, and nothing else. I suppose if you use an inferior brand you could add some mustard or something, but with a good smoked kipper nothing else is needed!
Added to scrambled eggs is also great, as already mentioned!