Computer won't boot or drive is not detected after cold boot, but is after warm boot or reset.

Some motherboards boot quickly before a hard drive has spun up and is ready. Thus, the drive might not be detected during a cold boot but be detected and function normally after a warm reboot or reset.
When this happens, it is generally because the motherboard boots more quickly than the hard drive. The drive is not ready when the computer cold boots.

There are a few options to resolve this:

• Warm boot the computer. This means that you would reboot the computer when the problem occurs. The hard drive will be ready after the reboot. This is a workaround solution, but not a final resolution.
• Set a delay in the BIOS so that the motherboard will wait a little bit for the hard drive to become ready.
  To accomplish this:
  1. Boot into the BIOS of your computer. See this example of helpful hints for how to do this.
  2. In the BIOS, locate HDD Pre-Delay, HDD delay, HD Timeout, or a similar option in the BIOS and set the number to 5 seconds or lower, depending. This may require a bit of trial-and-error to see which option is best for your computer.
  3. Save and reboot to test.
  4. If this option isn't present, disable Quick Post or Quick Boot in the BIOS. This may delay boot long enough for the drive to become ready.
• Enabling floppy disk scan or other similar options to lengthen the boot process may resolve this issue as well.