WINDOWS8 and "Safe Boot" (5)

" Safe Boot the English name "secure Boot" is not a feature of Windows 8, why would windows 8 and "secure Boot" be linked together? Because preinstalled WINDOWS8 brand computers all use the Uefi BIOS, most of them contain "Safe boot"! So what is "safe boot"?

Secure boot is a UEFI protocol that allows only "signed and authenticated" code or programs to be loaded before starting the operating system. The UEFI programs are listed in the two database "signature Database" and "revoked Signature database", similar to "whitelist" and "blacklist"! Microsoft can update "whitelist" and "blacklist" by signing key in "Key encryption password database".

Microsoft signed the signature program in the database . the WINDOWS8 system "OS Loader". OEMs store the above three databases in the motherboard's "Nv-ram" to enable the use of "secure Boot" to start WINDOWS8. This is why it is not possible to install Windows7 by default for WINDOWS8 branded machines, but we can disable secure boot in the UEFI BIOS .

Case: Pre-installed WINDOWS8 brand machine installation Other systems

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If you are in a UEFI BIOS environment, you must ensure that: 1. UEFI is supported by the operating system (described earlier); 2. The operating system supports secure boot. Therefore, the installation of Windows7 must: 1.windows7 64-bit (meet the conditions 1); 2. Disable secure boot in the UEFI BIOS(condition 2 is met).

Note: Previously said that 64-bit UEFI environment can only be installed in 64-bit systems, in a 32-bit UEFI environment only 32-bit systems can be installed. So the preinstalled WINDOWS8 64-bit branded machine (X64 's uefi Environment ) wants to switch to 32-bit Windows and only switches to Legacy BIOS mode!

WINDOWS8 and "Safe Boot" (5)