First message and new-line characters
The plain-text ASCII messages start near the end of the file; the first is at address h3B36C (byte number 242,540 in decimal). If you look at this location, you'll see bytes spelling the message "Windows could not start because of an error in the software.", followed by the bytes h0D h0A, followed by more text. The two bytes h0D h0A indicate the start of a new line. If a message ends in this, you should make sure it still ends that way after editing. Otherwise, the bootloader will not be on a new line by the time it needs to show the next message, which will look messy.

The first plain-text message, with new-line bytes highlighted in red.

Although it is safe to add more new lines if you want to, you must remember that there is a limit to how many lines can be displayed on the screen. For example, even if one message may have just 3 lines of text, the bootloader may additionally be showing other messages on the screen. If it exceeds the maximum number of lines able to be shown, then text will be rendered weirdly, making it hard to use any menus that may be displayed, but it's not fatal (Windows will still be able to boot).

My first attempt at displaying ASCII text used too many lines; this is how it looked.

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- Robbi-985 aka SomethingUnreal