Someone has a minor case of OCD.
Try Right click then Open File with?
Eh oh well don't care anymore. Will go away when I restart maybe... haven't restarted computer in a week or so... xD
That's srs bsns. You haz super virus.
Open any folder>Tools>Folder Options>File Types>Advanced>Change Icon
Restarting will probably help. Delete icon caches.
Change Open With to something else, then back to Notepad.
Stop fucking with shit.