It looks like windows thinks they are .pdf files, at least judging from the Adobe PDF icon it's using for each of them.

"sort the file on-screen by date entered"? Do you mean by the "Date modified" field shown on the screen? If so, just click on "Date modified" at the top of that column. Otherwise, dunno.

EDIT: if you want to sort by the date you've embedded into the file names themselves, then you'll have to first use a proper date format, with Year-Month-Day-Hour-Minute order, rather than the order you're currently naming them with.

Cheers