Decoding POST Messages
After the POST and boot sequence have advanced to the point at which they have use of the video to display messages, they can display a numerical error message to indicate a failure that occurred during the POST or boot sequence.
|2xx||Main memory errors|
|5xx||Colour graphics adapter errors|
|6xx||Floppy disk controller errors|
|17xx||Hard drive controller errors|
Installing new hardware, especially hard drives, can result in error messages like 'no boot disk'. This will have happened when you switch on the computer that you have just built.