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Disable CSM - Boot Windows 7 x64?

SlackROG
Level 10
I tried to disabled CSM in the bios of 2202, but when I try to start Win7 it just restarts...

Is it possible to disable CSM and boot Win7 x64?
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42 REPLIES 42

Korth
Level 14
Don't know if it's possible

But, assuming Windows would boot properly, what advantage would you gain from disabling CSM?
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

SlackROG
Level 10
Hi Korth,

Well for starters I was looking at this from Linux, since I dual boot.

With CSM enabled you get this in Linux logs;

Your system is not currently configured to drive a VGA console on the primary VGA device. The NVIDIA Linux graphics driver requires the use of a text-mode VGA console. Use of other console drivers including, but not limited to, vesafb, may result in corruption and stability problems, and is not supported.

If I disable CSM this goes away, so for Linux I was happy about that, first mission accomplished LOL...

Next I was able to boot Win10 with CSM disabled, so I know it's not my hardware, and I read online that others are doing it.

I remember that in rufus I had it set to the mbr/gpt settings, so I just went back to rufus and installed Win7 this time as only the uefi/gpt mode and I noticed the install completed looking different, creating the bootx64.efi which I didn't have before, I added it in manually before, so maybe now it's going to work.

Off to try and boot this new usb format I did, will report back on how it goes... 😉

I thought disabling CSM kills off Legacy since it's not needed, improving performance and speed...

SlackROG
Level 10
AHHH it just reboots... 😞

So I can't get this working...

Hmm

haihane
Level 13
SlackROG wrote:
I tried to disabled CSM in the bios of 2202, but when I try to start Win7 it just restarts...

Is it possible to disable CSM and boot Win7 x64?


isn't CSM (compatibility support module) the other word for secure boot?

  • CSM = enable legacy support, or in other words, bios detects devices and tries to boot whatever it finds with MBR
  • CSM being enabled means secure boot = off?


i don't think i've tried installing windows 7 with CSM disabled (there's no option for Secure boot on CHVF-Z). but first, a little backstory:
when i bought this board (2013?), if i remember it correctly, the board comes with CSM = Enabled as default. the crosshair V formula Z isn't a full system upgrade, per se, but rather a incremental purchase. i bought the board and also the FX cpu to replace the previous MSI board that died. you know the feeling when you got a new board, and just wanted to work on it asap, to get everything up and running? yeah that.

over the years, i tried software raid based on how-to-geek's guide (i used mirror mode), and finding out that if a power drop happens, the dual 6tb spends hours syncing. i think it was around the time i joined this ASUS forum that i started experimenting with hardware raid (creating, breaking, recreating arrays, trying out different install modes) like a madman. anybody remembered digging though AMD drivers to find that RaidXpert install files? since the RaidXpert that came with the motherboard is pretty much outdated.

remembering back, i think i might have tried to get Windows 7 installed on UEFI mode (secure boot, CSM disabled, UEFI), and failing, and spending hours trying to figure out why. turns out, that was because my ASUS Radeon 6950 wasn't UEFI compatible. this dawned upon me when i opened GPU-Z.

but hey, if it works, why bother tinkering, eh? (you might think. but i wasn't satisfied. and there's no way i'd buy a new GPU just to test installing Windows on UEFI mode). fast forward a couple of years and windows 10 comes as a free upgrade, and coupled up with me having purchased a R9 290X (with proper UEFI support), and that enabled me to try UEFI. but everything was running so fine! i was zealous when it comes to my OS' cleanliness and stability so i didn't feel the need for a reinstall.

i think it was when i purchased this Samsung SSD and failing to clone it properly. contrary to popular belief, Samsung SSD migration tool don't go a good job at all when cloning from a HDD to SSD. i found myself the need to break my RAID 1 OS array, thinking to myself: am i gonna break stuff and my clean OS go up in smoke? fingers crossed when i finally hit the break array button. luckily it worked fine. the cloning to SSD went without a hitch. it was until i got back into OS loaded from SSD that i felt something was off. in disk optimizer view, the OS drive is labeled as HDD. i saw the Optimize button, i had a bad feeling about it, but pressed it anyway.

i skipped a heartbeat when it actually tried to defragment. it was also the time i decided a proper reformat and reinstall was in order.

I remember that in rufus I had it set to the mbr/gpt settings, so I just went back to rufus and installed Win7 this time as only the uefi/gpt mode and I noticed the install completed looking different, creating the bootx64.efi which I didn't have before, I added it in manually before, so maybe now it's going to work.


heh, fellow rufus user. hello.
Rufus > windows media creation tool, any day!

anyway, continuing on. perhaps, i haven't actually encountered your problem (installing windows 7 on uefi), though for some reason, i think i might have tried this on someone else's computer if not on my own. people look for me to fix their PC (pfft). i don't charge money for it, but i'm one grumpy teacher, i'd lecture them on things they shouldn't install, things they should be doing to keep their system clean, etc. i think there maybe one instance where i fix this guy's PC, using the experimental Creator's update feature (MBR2GPT), explaining to in advance him the risk(s) involved since i would have no idea what might happen because his Graphics card isn't UEFI ready. funnily, it worked.

the mystery remains to this date why his system worked. i handmade his Windows10 USB though using rufus. in fact, i carried two USBs when going over to his place to fix it, one Windows USB (MBR), one Windows GPT install. (i used the GPT install usb).

god, it's getting too long again. sorry, got carried away again.


tl;dr: i think you may need to actually reinstall windows on UEFI/ GPT environment, make sure the disk where you'd like windows is installed to is formatted as GPT, check and remove any leftover MBR partition.

i'm hoping your linux isn't on the same physical drive as where you'd want windows to be (if you're going to dualboot), and whether you'd want to choose to extract linux bootloader into Windows, letting windows handle dual booting (BCDedit), or just let GRUB2 handle the bootlader.


Question: Linux is happy with UEFI now? last i tried linux (ubuntu variant), it wasn't happy with UEFI.
no siggy, saw stuff that made me sad.

Hi,
Not exactly sure why you'd want to disable CSM ?
Which enables compatibilty legacy mode for yes win-7 to be installed.

Fast start on the other had can and should be disabled.
Secure boot should also be disable
Also by switching OS Type to Other OS
Then Key Management which is secure boot and Clear secure boot keys then finally secure boot will show as disabled.

A windows update confirmed switching to Other OS a while back
http://www.asus.com/support/FAQ/1016356/
[SIGPIC][/SIGPIC]

SlackROG
Level 10
@haihane, I didn't just read that you tried to defrag an SSD did I? LOL Cause if I did, you don't defrag an SSD.

From what I read Windows 7 only supports UEFI 2, which is why supposedly I can't get it installed, and need CSM enabled.

@ThrashZone, Secure Boot from my understanding has nothing to do with getting Win7 installed, or working with EFI.

The disk is GPT partition... So not sure why I need to disable Secure Boot since the BIOS is set as Other OS and everything boots up fine, I don't see that Secure Boot is getting in the way of anything.

Yes Linux is on the same drive, different partition of course... 🙂

GRUB works just fine dual booting and Linux works easy/great with EFI.

SlackROG wrote:
@haihane, I didn't just read that you tried to defrag an SSD did I? LOL Cause if I did, you don't defrag an SSD.

From what I read Windows 7 only supports UEFI 2, which is why supposedly I can't get it installed, and need CSM enabled.

@ThrashZone, Secure Boot from my understanding has nothing to do with getting Win7 installed, or working with EFI.

The disk is GPT partition... So not sure why I need to disable Secure Boot since the BIOS is set as Other OS and everything boots up fine, I don't see that Secure Boot is getting in the way of anything.

Yes Linux is on the same drive, different partition of course... 🙂

GRUB works just fine dual booting and Linux works easy/great with EFI.


Hi SlackROG, I think you are correct, Win7 can only be booted using legacy BIOS with MBR partitioning, or with Class 1 or Class 2 UEFI (and GPT partition), which emulates legacy BIOS so it can boot Win7. I am thinking your "UEFI 2" probably refers to class 2 UEFI bios mode. See the following from "UEFI Secure Boot in Widows 8.1" by Sushovan Sinha:

The Evolution of Platform Firmware are classified as:
Class 0: Pure BIOS Firmware.
Class 1: UEFI Firmware which emulates as BIOS only. No UEFI support is provided. This was used by Platform Manufacturers to transition to UEFI standard while essentially maintain a BIOS platform, as most OS of that time were not UEFI aware.
Class 2: These Platforms support both UEFI and Legacy BIOS via CSM. Majority of platforms shipping today are Class 2 platforms. Class 2 platform with CSM enabled functions like a Class 1 platform. Here the UEFI BIOS firmware though inherently UEFI, provides no UEFI support and this is where the use of the term UEFI gets misleading sometime.
Class 3: These platforms boot purely through UEFI firmware without any Legacy BIOS support. Class 3 platforms do not have a Compatibility Support Module. Class 2 platform with CSM disabled functions like a Class 3 platform.

If your Win7 boot drive is partitioned as GPT and not MBR, it is called "Hybrid MBR" and still boots using a Legacy BIOS as required by Win7 as far as I know. You should need to have CSM enabled for this system to boot. Because CSM allows for older OS bootloaders and Option ROMs whose signatures are not in the Secure Boot database, you can't have CSM and Secure Boot enabled at the same time. With CSM disabled, you can have Secure Boot enabled or disabled. You can check your partition layout. With MBR for Win7 it should have a System and a Boot partition:
68757
while with the GPT partition for UEFI (or class 2 UEFI for emulating legacy boot) you will have an EFI partition (Extensible Firmware Interface), system and recovery partitions:
68758

I don't know why your Win7 system keeps rebooting, but maybe this info will help you troubleshoot.

CSM IS ENABLED BY DEFAULT, so people who want a pure UEFI boot system will want to disable CSM before installing the OS.

Here is the link to the discussion by Sushovon Sinha “UEFI Secure Boot in Windows 8.1” https://answers.microsoft.com/en-us/windows/forum/windows8_1-security/uefi-secure-boot-in-windows-81...

AHHHHH THESE CMDS WORK! WoOT 🙂

I started Win7 as normal with CSM enabled, then I ran each command one at a time, then rebooted, went into the BIOS and disabled CSM and it works!

Be sure to run the cmd prompt as Admin to do this! 😉

The only thing, I no longer see the Windows 7 startup screen, so I rebooted and unchecked the "No GUI boot" option and it works, not sure why someone removed this with these cmds I found online... Hmm

Click the Start button and in the Run or Search for programs and files text box, type msconfig and press Enter. ...
Click on the Boot tab. ...
On the Boot tab, uncheck the "No GUI boot" option.
Click OK.


It does boot a little faster with it disabled. 😉

Now to be honest this is a bit confusing, because the point of what I read online is that what is causing the issue is a lack of support for the VGA, so it's all be disabled. Now if that was 100% true, I personally don't get how I'm able to have the GUI boot enabled? Maybe someone can shed some light on this?

So bcdedit /set quietboot on doesn't have to be used if you still want the Boot Windows 7 Start Screen...

So try it and profit, just be sure to make a backup first! 😉

rem disable vga.sys 640x480 16 colors
rem ren %SystemRoot%\system32\drivers\vga.sys *.off
set Services=HKLM\SYSTEM\CurrentControlSet\Services
reg.exe add "%Services%\Vga" /f /t REG_DWORD /v "Start" /d 4
reg.exe add "%Services%\VgaSave" /f /t REG_DWORD /v "Start" /d 4

rem disable VGA at bootmgr
bcdedit.exe /set {current} bootlog yes
bcdedit.exe /set {current} bootstatuspolicy IgnoreAllFailures
bcdedit.exe /set {current} novesa on
bcdedit.exe /set {current} quietboot on

SlackROG wrote:
AHHHHH THESE CMDS WORK! WoOT 🙂

I started Win7 as normal with CSM enabled, then I ran each command one at a time, then rebooted, went into the BIOS and disabled CSM and it works!

Be sure to run the cmd prompt as Admin to do this! 😉

The only thing, I no longer see the Windows 7 startup screen, so I rebooted and unchecked the "No GUI boot" option and it works, not sure why someone removed this with these cmds I found online... Hmm

Click the Start button and in the Run or Search for programs and files text box, type msconfig and press Enter. ...
Click on the Boot tab. ...
On the Boot tab, uncheck the "No GUI boot" option.
Click OK.


It does boot a little faster with it disabled. 😉

Now to be honest this is a bit confusing, because the point of what I read online is that what is causing the issue is a lack of support for the VGA, so it's all be disabled. Now if that was 100% true, I personally don't get how I'm able to have the GUI boot enabled? Maybe someone can shed some light on this?

So bcdedit /set quietboot on doesn't have to be used if you still want the Boot Windows 7 Start Screen...

So try it and profit, just be sure to make a backup first! 😉

rem disable vga.sys 640x480 16 colors
rem ren %SystemRoot%\system32\drivers\vga.sys *.off
set Services=HKLM\SYSTEM\CurrentControlSet\Services
reg.exe add "%Services%\Vga" /f /t REG_DWORD /v "Start" /d 4
reg.exe add "%Services%\VgaSave" /f /t REG_DWORD /v "Start" /d 4

rem disable VGA at bootmgr
bcdedit.exe /set {current} bootlog yes
bcdedit.exe /set {current} bootstatuspolicy IgnoreAllFailures
bcdedit.exe /set {current} novesa on
bcdedit.exe /set {current} quietboot on


Congratulations! I am glad smart people are out there tinkering with these cmds before you get to try them on your own computer 😄
The legacy boot is still working because it boots up Win7, but with CSM disabled! There's an educational opportunity in there somewhere.