This is the last thing the BIOS does before it tries to load the OS.
Some BIOSs used to show the message 'Loading OS' before they started loading, but most modern ones don't. They just start loading as soon as they've finished "verifying DMI Pool data".
If your PC stops at that point, it usually means that the BIOS had started loading the OS, but something caused the loading to fail (e.g. files missing, or hard disk corrupted).