If your system is configured to use USB drives as the first bootable device and you leave a nonbootable USB flash drive plugged into your system (either directly or into a USB hub connected to your system), your system won’t boot. However, you can also use your system’s DVD or BD (Blu-ray) drive for these tasks. We recommend changing the boot order on Windows 7 computers if TIP If you change the boot order to remove USB flash drives or put them after the system hard disk, you can always change the boot order in the future to place USB drives first if you need to run diagnostic programs or install a new operating system.
Windows 8.1 (unlike Windows 8) does not support the creation of a CD or DVD repair disc, although you can use your Windows 8.1 distribution media as a repair disc. At startup, they’re typically caused by problems with hard disk device drivers.
With Windows 8.1, if your system supports booting from a USB drive, you should create a USB recovery drive instead. If you turn on your Windows computer and, instead of seeing the Windows login screen or desktop, you see a screen similar to the one shown in Figure 8.5, you have a STOP error, also known as a “Blue Screen” or BSOD (“blue screen of death) error. If a blue screen error appears after you have booted to the Windows desktop, it could be caused by corrupt apps, corrupt device drivers, or memory problems.
When you see a BSOD error, be sure to record the numbers listed after the STOP message, such as STOP: 0x0000001E, or 0x1E for short.
Before you make the switch, you need to enable Windows to use AHCI drivers when necessary.
The easiest way for Windows Vista and Windows 7 is to use the Fix-It wizard available from
When a system has problems starting, it might display error messages at startup.
These messages might come from the system BIOS (ROM BIOS or UEFI firmware) or might be generated by Windows.
Almost all hard disks are configured using Auto as the hard disk type.
Thus, if the setup information is lost, the default (normal) setting is Auto and the drive will be properly detected.
This page also details manual Registry changes that make the same changes as the Fix-It Wizard.