The best way to design an error message is to figure out why you need it in the first place, and eliminate that "need" (i.e. you don't display any message). If

The best way to design an error message is to figure out why you need it in the first place, and eliminate that "need" (i.e. you don't display any message). If the proverbial house isn't burning down, the user doesn't need to know. Most messages can be non-modal, tucked away in a conspicuous spot but not immediately stopping whatever the user is doing. Even those can often close themselves, not requiring acknowledgment, ever. Somewhere along the line, people forgot that computers are supposed to be tools, and decided it was okay to put up with constant interruptions to their work. I swear, using Windows is like raising a small, needy child.