my notepad.exe disappeared?! i need to open a txt file and it's gone. (tried searching for teh file, but found only shortcuts leading to nothing). don't know what happened, but how can i get it back?

I use notepad.exe on an XP SP3 machine. I've lately noticed that the paper size is defaulting to A4, and I can't seem to switch it back to Letter. I've changed the setting in the Page Setup options, ...