msi mpg z490 help

guy.bir15aa02dd

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Nov 26, 2021
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HI i have built a pc up using this motherboard every thing boots up straight in to bios every thing is present and correct i've set the bios to boot to windows in the boot order.
Where i am stuck is when i press save and exit when the computer reboots in goes straight back to bios any have a ideal if i have overlooked some thing.
 

citay

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Why it's not booting your old installation: Your Windows was installed with the previous motherboard's BIOS in CSM/Legacy mode.

A modern BIOS can be in two modes: Legacy/CSM (Compatibility Support Module) and the newer UEFI (Unified Extensible Firmware Interface) mode. Since all BIOSes are UEFI BIOSes nowadays, naturally they work best when set to UEFI mode. But also, every modern BIOS can be set CSM/Legacy mode, in order to behave like an old BIOS from many years ago. This is so it can work with older operating systems which have no or only limited support for UEFI, such as Windows 7. The problem lies in the fact that switching between those two BIOS modes after you have installed Windows will make the boot process fail.

When Windows detects a CSM/Legacy BIOS during installation (for example on an old board or an old BIOS), it prepares the boot drive to have an MBR (Master Boot Record).
When it detects a UEFI BIOS during installation, it will prepare the boot drive with a GPT (GUID partition table) instead of an MBR. The BIOS set to either mode (CSM vs. UEFI) will only boot from a drive that was prepared accordingly for that mode (CSM needs MBR, UEFI needs GPT).

As for the solution, the question is, can you back up your data and then do a fresh install of Windows with the BIOS in UEFI mode, like it is now? That's the cleanest way by far.
You are trying to use a Windows installation from an old system, but Windows sets a lot of internal variables according to the hardware and configuration it detects during installation. So the best thing would be to do a fresh install of Windows using a USB stick prepared with the latest Media Creation Tool (also available for Windows 11). For that, run the tool, then select "Create installation media (USB Flash drive)". After it's done, boot from the drive/stick by pressing F11 during boot for the boot menu and select the drive/stick there. Once in Windows, install the Intel Chipset drivers first.

There are also two quick and dirty fixes to make it boot again, but they have downsides:

The first is to set the new board's BIOS to CSM/Legacy mode. However, CSM mode is outdated, it was only needed for Windows 7, but for anything after that, UEFI mode is better, and Windows 11 will actually require it. You can't install (or upgrade to) Win11 when the BIOS is in CSM/Legacy mode. So this will only cause problems down the road.

So a better option is to convert the boot drive from MBR to GPT: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10
There's other tutorials you can find on that procedure as well. It doesn't take long, and the BIOS can use the drive as a boot drive in UEFI mode afterwards.

But even that second option, where you at least have the BIOS set to the modern UEFI mode, will still have the issue of Windows setting itself up according to the hardware it detects during installation. If you skip that part, things like the turbo modes for the CPU might not work properly. So the cleanest way will always be a fresh install of Windows.
 
Last edited:

guy.bir15aa02dd

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Joined
Nov 26, 2021
Messages
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Why it's not booting your old installation: Your Windows was installed with the previous motherboard's BIOS in CSM/Legacy mode, or the previous board had an old BIOS that wasn't UEFI yet.
A modern BIOS can be in two modes: Legacy/CSM (Compatibility Support Module) and the newer UEFI (Unified Extensible Firmware Interface) mode. Since all BIOSes are UEFI BIOSes nowadays, naturally they work best when set to UEFI mode. But also, every modern BIOS can be set CSM/Legacy mode, in order to behave like an old BIOS from many years ago. This is so it can work with older operating systems which have no or only limited support for UEFI, such as Windows 7. The problem lies in the fact that switching between those two BIOS modes after you have installed Windows will make the boot process fail.

When Windows detects a CSM/Legacy BIOS during installation (for example on an old board), it prepares the boot drive to have an MBR (Master Boot Record). When it detects a UEFI BIOS during installation, it will prepare the boot drive with a GPT (GUID partition table) instead of an MBR. The BIOS set to either mode will only boot from a drive that was prepared accordingly for that mode.

As for the solution, the main question is, can you back up your data and then do a fresh install of Windows with the BIOS in UEFI mode, like it is now? That's the cleanest way by far.
You are trying to use a Windows installation from an old system, but Windows sets a lot of internal variables according to the hardware and configuration it detects during installation. So the best thing would be to do a fresh install of Win10 using a USB stick prepared with the latest Media Creation Tool (also available for Windows 11). For that, run the tool, then select "Create installation media (USB Flash drive)". After it's done, boot from the drive/stick by pressing F11 during boot for the boot menu and select the drive/stick there. Once in Windows, install the Intel Chipset drivers first.

There are also two quick and dirty fixes to make it boot again, but they have downsides:

The first is to set the new board's BIOS to CSM/Legacy mode. However, CSM/Legacy mode is outdated, it was only needed for Windows 7, but for anything after that, UEFI mode is better, and Windows 11 will actually require it. You can't install (or upgrade to) Win11 when the BIOS is in CSM/Legacy mode. So this will only cause problems down the road.

Another option is to convert the boot drive from MBR to GPT, https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt
There's other tutorials you can find on that procedure as well.

But even that second option, where you at least have the BIOS set to the modern UEFI mode, will still have the issue of Windows setting itself up according to the hardware it detects during installation. If you skip that part, things like the turbo modes for the CPU might not work properly. So the cleanest way will always be a fresh install of Windows.
Hi and thank you i did not know that i will do a clean install thanks again.
 
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