The effect of "CSM" on the installation of Windows

CSM Full name compatibility support module, a compatibility support block, is a special module of UEFI that provides compatibility for systems that do not support UEFI. Currently, the WINDOWS8 fully supports the 64-bit uefi that is not fully supported by Uefi,windows7. Therefore, the installation of Windows7 in UEFI BIOS must turn on the CSM, most computers can be turned on automatically or manually, and a few computers will force the CSM off.

Pre-installed WINDOWS8 brand machines are UEFI BIOS, the first use of friends to reload the system has been in trouble, the specific solution before the detailed introduction. The following is specific to the pre-installed WINDOWS8 brand installation WINDOWS7 BIOS setup problem, because Windows7 does not fully support UEFI, if you want to keep the pre-installed system under the premise of Windows7 can not set the BIOS to "pure UEFI", and must be disabled " Secure Boot ".
Set EFI Bios:boot Mode[uefi/legacy], set to UEFI.
Launch csm[enabled/disabled], set to Disabled.
Launch Csm[uefi/legacy], set to UEFI.
(The above settings generally remain the default)
Set compatibility mode: CSM support[yes/no], set to Yes.
OS Optimized defaults[enabled/disabled], set to Disabled.
OS Optimized Defaults[win8 64bit/others], set to Others.
(The above settings are generally the opposite of the default)
Disable secure boot: Secure boot[enabled/disabled], set to Disabled.
(The above settings are generally the opposite of the default)
Some computers are forced to "pure uefi", then the BIOS must be set to legacy mode in order to install WINDOWS7, but in this case you need to repartition the hard disk and change to "MBR partition scheme"

Set EFI Bios:boot Mode[uefi/legacy], set to Legacy.
Launch csm[enabled/disabled], set to Enabled.
Launch Csm[uefi/legacy], set to Legacy.
(The above settings are generally the opposite of the default)
Set compatibility mode: CSM support[yes/no], set to Yes.
OS Optimized defaults[enabled/disabled], set to Disabled.
OS Optimized Defaults[win8 64bit/others], set to Others.
(The settings above are generally the opposite or no need to be set)
Disable secure boot: Secure boot[enabled/disabled], set to Disabled.
(The settings above are generally the opposite or no need to be set)

The specific situation should be analyzed specifically, some computers set the BIOS Mode[uefi only/legacy support] to Legacy, and the boot priority set to UEFI first also means "CSM is turned on in UEFI mode."

This article is from the "Green Home" blog, please be sure to keep this source http://77jiayuan.blog.51cto.com/386386/1545293

CSM's impact on installing Windows