Annette recently updated to Windows 10, but now she has to boot up twice in order for the computer to completely boot up. Leo says there could be many reasons for a halted boot. External devices are the easiest things. Turn off Windows Fast Boot. It's a terrible feature that doesn't really speed up your computer. But what it implies is that your computer isn't warm enough when it boots up the first time, and so it stalls. This can happen with older computers. It can also be a sign of your hard drive failing. A new hard drive will solve it, and Leo recommends a solid-state drive (SSD).
Ken has reinstalled Windows 10 on an old Dell laptop, and it's running way too slow. So he's trying to install Linux instead. But it won't boot from the USB key no matter how hard he tries. Leo says to make sure you format the USB key into a UEFI format. That should enable it to read it.
Doug recently replaced a power supply, and now the computer won't boot up to his main hard drive. Leo says that the SATA cables may have been swapped and that can confuse the BIOS. He should disconnect the data drive and see if it boots to the boot drive. If it doesn't, he can swap out the cables. He should also clear the configuration data in the BIOS so that it can reset. There's also a possibility that his boot drive is damaged, so he should check that. Getting rid of the master boot record on his data drive will prevent confusion as well.
Penny has an old tower computer that she wants to get rid of. Leo suggests keeping the hard drive and donating the rest of the PC. She tried to boot it up to move the data off the hard drive, but it won't boot. Leo suggests that she check her keyboard connection. Sometimes a computer won't boot if a keyboard isn't properly connected. The BIOS battery or motherboard battery could have died. The hard drive may have gotten stuck. It's called "stiction." Penny should try taking out the hard drive and putting it into an external enclosure to see if she can still read the data.