The first, with me, was MSKB article limited to Windows 2000. But the second (http://zotline.com/shownote.zot/NoteNum/2504.html) seems to be about the same as you (on Windows 95).
If you find any solution in one of the other hits or in the discussion groups, it would be interesting to read it here.
For the moment, it's just one of those glitches that a reboot solves. That means that something unknown has happened since the last boot causing just that condition that Notepad doesn't like somewhere in the system. It might be impossible to find out, and it certainly can be hard.
The workaround presented in the last line of the link given (use Wordpad) might be the best for you.
Or use Notepad+ (a free Notepad replacement) from http://www.mypeecee.org/rogsoft/
I use it routinely for website maintenance, and I particularly love the 15 open windows and the File>Reopen. Very nice, very reliable. Note the installation procedure carefully if you want it to really replace Microsofts Notepad (and make a backup copy of that program to start with, of course).
Somewhat less basic, but free also, is Editpad Lite from http://www.editpadlite.com/editpadlite.html
If your editing is more demanding, you can pay for a more powerful Pro version, but depending on your use there are other paid editors that might be better suited for you (like editors that 'know' programming languages and add color to the syntax) if you are a programmer or a html-editor if you use it for a html.
You don't tell for what purposes you use Notepad, but I get the impression you do it more or less regularly. Then I should certainly advice to you try these alternatives, be it for their added functionality or simply because they work without glitches. But, as I said, a paid alternative might be even better for you.
Hope this helps.
Kees
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic