I was born in 1983, so I can't compete with some of this stuff, and I haven't got all that many old files on my current computer because most of it's constantly being updated. However, I have retained an extremely old DOS game from 1985/86 called Sopwith Camel which is just a single *.exe file. It was the first computer game I ever played, sometime in '86 on my grandfather's old 286. When I got my first computer for Christmas in '93 (a 486, 66MHz) I copied the game over and I've been holding onto it ever since.