If you find .nfo files on your computer and you try to open them, you'll probably get an error that tells you something along the lines of: "System Information cannot open the NFO file. It might be corrupted or an unrecognized version."

Just ignore this. The .nfo files are just straight text files; the problem is that Windows tries to open them with System Information instead of just using a text editor. To teach windows how to open .nfo files, right click on the file and select "Open With -> Choose Program..." and then choose the text editor. You want to select the "Choose Program..." option even if the program you want is show in the menu because when you do this, you can then check the box that says "Always use the selected program to open this kind of file" box so that in the future, windows will open all .nfo files using the program that you select.