BIOS update is a must. The early BIOS usually has lots of bugs, you don't want to troubleshoot for days when everything could've been avoided with a BIOS update to the latest version. Leave the BIOS in UEFI mode.
In general, i would do it like this with a new system:
1) Perform a quick basic stability test using
Memtest86 Free. Prepare a USB stick with Memtest86 (on another PC) and boot from it by pressing F11 for the boot menu (press it a couple times right after turning on or rebooting the new system). There will be two partitions on the USB stick, so it will have two entries in the F11 boot menu, one of them (with modern systems, usually the lower one) will boot Memtest86. Two passes without errors is usually sufficient, and the row hammer tests at the end, which take a long time, can be skipped.
2) Update the BIOS to the newest version from the support site (extract latest BIOS ZIP file to USB stick on another PC, enter BIOS on the new system by pressing DEL a couple times after turning it on, enter M-FLASH from within the BIOS, and select the file on the USB stick to update from). Such a BIOS update is crucial, unless you want to suffer from BIOS bugs that are long solved in newer versions. After updating, enable XMP for the RAM and set up your
fan curves in the BIOS. XMP makes the RAM run at the proper speed of for example DDR4-3600 instead of the safe default of DDR4-2133 (or DDR5-6000 instead of DDR5-4800).
Now it's best to run Memtest86 again, to see if XMP makes the RAM unstable or not. The RAM has to be in slots A2 and B2 (2nd and 4th from the left), by the way. Memtest86 is not the last word on RAM stability, mind you, it's just to get a quick idea if it's worthwhile installing Windows or not. Because if that test shows errors, it's too unstable to do anything, it has to be made stable first.
For boards using an ASMedia chipset for two extra SATA ports, it should be disabled in the BIOS after the update, because that chip tends to cause trouble, see
here.
3) Install Windows.
For that, you would download the latest
Media Creation Tool for Windows 11. Freshly prepare a USB drive with it (obviously again on another PC), and then boot from it by pressing F11 for the boot menu after turning on the PC, and select the USB drive there. I explained the Windows installation procedure a bit
here. There is no need to set the boot order manually, Windows will automatically add itself as the boot drive. It's crucial to use this Media Creation Tool to prepare a USB stick, because it will download the latest version of Win11. When you use an older Win11 installation DVD you might have, it can cause problems later.
Only have the drive attached that you want to install Windows to. Temporarily disconnect the other drives, so the Windows installer doesn't get confused. You can add them later again, when Windows was installed.
12th/13th/14th gen CPUs have P-cores and E-cores, and Win11 has improved thread scheduling to put workloads on the proper cores, so certain workloads don't accidentally get stuck on an E-core. With two free tools linked
here, you can make it look like any Windows, i made it look and feel like Win10. In general, Windows 11 is the OS of choice nowadays (Windows 10 support ends in October 2025).
4) For Intel: Install the Intel Chipset drivers first, then Serial I/O, Intel GNA Scoring Accelerator and Management Engine (all from the MSI support site). These will get rid of all the unknown devices in the device manager and set everything up correctly for the power saving modes to work and so on. For AMD: Just the latest AMD Chipset Driver. Also LAN driver, and let Windows Update check for missing updates, a reboot (or several) will be needed. The
WLAN,
LAN and
Bluetooth drivers ("Driver64" of each) you can get from Intel directly, they are newer. Or on a board with Realtek LAN, those drivers are
here.
5) For recent Intel CPUs, here is a guide to optimize how they run:
Guide: How to set good power limits in the BIOS and reduce the CPU power draw.
Here is a video with some general PC building advice: