How to Set Up Bios for New Custom Gaming Pc: Step-by-Step

Building a new custom gaming PC is exciting until you hit the power button and nothing seems optimized. If the BIOS is not set up correctly, your expensive RAM might run at half speed, your NVMe drive won’t boot, your fans scream at 100%, and you leave 10 to 15% of gaming performance on the table. Worse, unstable settings can cause random crashes, boot loops, or failure to detect your graphics card. Getting the BIOS right from the start ensures every component communicates properly, stays cool, and delivers the frames you paid for.

What You Need

Step-by-Step

Step 1: Do a First Power-On and Enter BIOS (2-3 minutes)

Connect your keyboard to a rear USB 2.0 port, plug your monitor into the graphics card if you have one, and connect power. Turn on the power supply switch, then press the case power button. Immediately start tapping the BIOS key repeatedly. For most boards including the MSI MPG Z390 Gaming Edge AC, that key is Delete. Some systems use F2. If you see the Windows logo, you missed it – hold the power button to shut down and try again. On first boot you should land in EZ Mode, a simplified dashboard showing CPU temperature, RAM capacity, drive detection, and fan speeds.

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Step 2: Check That All Hardware Is Detected (3-5 minutes)

Before changing anything, verify detection. Confirm your CPU model and temperature are shown. At idle in a 68-72 degree room, a modern air-cooled CPU should sit around 30-45 degrees Celsius. Check that total RAM matches what you installed (e.g., 16GB, 32GB) and that all sticks are listed. Check Storage – your SATA SSD/HDD and M.2 NVMe drive (2280 size, 0.1-0.3 pounds) should both appear. If a drive is missing, power off, reseat its power and data cables or M.2 screw, and try again. Do not proceed until everything is detected.

Step 3: Load Optimized Defaults (1 minute)

In EZ Mode or Advanced Mode, look for Load Optimized Defaults and confirm Yes. This resets any stray settings from manufacturing or previous testing to stable, factory-recommended values. It is the safest starting point for a new build and prevents hidden overclocks or voltage errors. After loading defaults, do not exit yet.

Step 4: Enable XMP / A-XMP for Your RAM (2 minutes)

This is the single biggest performance fix. By default, DDR4 often runs at 2133 or 2400 MHz even if you bought 3200 or 3600 MHz RAM. Find the XMP or A-XMP toggle, usually at the top of the MSI BIOS screen. Change it from Disabled to Profile 1. The BIOS will automatically set the correct frequency, timings, and voltage (typically 1.35V for DDR4 XMP). Save and confirm the new speed is displayed. For a 16GB (2x8GB) 3200 MHz kit costing $35-$65, this can improve game frame rates by 5-15% in CPU-bound titles.

Step 5: Set Boot Order and Storage Mode (3-4 minutes)

Go to Settings > Boot. Set Boot Mode to UEFI if you plan to install Windows 11. Ensure SATA Mode is set to AHCI, not RAID, unless you are running multiple drives in RAID. Under Boot Priority, drag your Windows USB installer to the top if you are installing Windows, or your primary NVMe/SATA drive to the top if Windows is already installed. If you have an M.2 NVMe drive, confirm M.2_1 is set to PCIe mode for full bandwidth up to 3000-3500 MB/s on PCIe 3.0 boards like the Z390.

Step 6: Configure Fan Curves and Cooling (4-5 minutes)

Go to Hardware Monitor. You will see fan headers for CPU Fan, Pump Fan, and System Fans 1-4. For air coolers and case fans (120mm or 140mm, 0.2-0.4 pounds each), use the Smart Fan graph. A quiet, safe curve many builders use is: 30% speed at 40 degrees Celsius, 60% at 65 degrees, 100% at 80 degrees. For AIO liquid coolers (240mm to 360mm radiators), set the pump header to 100% or PWM/DC as per cooler manual. This keeps idle noise down to 25-35 decibels while still protecting the CPU under load.

Step 7: Enable Resizeable BAR and Above 4G Decoding If Supported (2 minutes)

On newer GPUs (NVIDIA RTX 30/40 series and AMD RX 6000/7000 series) you can gain a few extra percent in some games by enabling Above 4G Memory / Resizable BAR. On MSI boards it is under Settings > Advanced > PCI Subsystem Settings. Set both to Enabled. If you have an older GTX 10 series card, leave this disabled as it will have no effect.

Step 8: Adjust Secure Boot and TPM for Windows 11 (2-3 minutes)

Windows 11 requires TPM 2.0 and Secure Boot for a standard install. In Settings > Security > Trusted Computing, ensure Security Device Support is Enabled. For Z390 and newer boards, Intel PTT acts as TPM. Then go to Settings > Advanced > Windows OS Configuration and set Windows 10 WHQL Support to Enabled or UEFI, and Secure Boot to Enabled. If you are installing Windows in 2026, this will prevent compatibility errors during setup without needing registry workarounds.

Step 9: Save, Exit, and Install Your OS (2 minutes plus OS install time)

Press F10 to Save Changes and Exit, confirm Yes. The system will reboot. If you have a Windows USB inserted, it should boot to the installer. Follow the Windows prompts to install to your fastest drive. After Windows is installed, revisit BIOS once more to confirm Boot Priority now shows Windows Boot Manager at the top.

Step 10: Update BIOS Only If Needed (10-15 minutes, optional)

Do not update BIOS unless you need support for a newer CPU, fix a bug, or your manual recommends it. If you do, download the latest BIOS file for your exact motherboard model onto a FAT32 USB drive from another computer, insert it, and use M-Flash in the BIOS. Keep power absolutely stable during flashing – a loss of power for even a second can brick the board. Never interrupt a flash. Most gamers never need to do this on a new build if the board already posts correctly.

Mistakes to Avoid

Forgetting to enable XMP is the most common error and leaves free performance unused. Another is plugging the monitor into the motherboard HDMI instead of the graphics card after setup, which forces games to run on integrated graphics. Avoid manually changing CPU voltages or overclocking on day one – use Auto and XMP only until your system is stable for a few days. Do not disable all fans to reduce noise; CPUs can hit 95-100 degrees Celsius and thermally throttle in seconds without airflow. Finally, avoid changing multiple settings at once and saving. Change one group, save, and test so you know what caused a boot failure if it happens.

How Often

BIOS setup is a one-time task for a new custom gaming PC. You only need to re-enter BIOS when you upgrade hardware like RAM, CPU, or storage, add more fans, or if you clear CMOS after a failed setting. Check for a BIOS update every 6 to 12 months, but only install it if the release notes list a fix or feature that applies to you. Fan curves can be tweaked seasonally if room temperature changes more than 10 degrees.

When to Call a Pro or Replace

Call for professional help if the PC will not post after multiple tries, shows a CPU or DRAM debug LED that stays lit, loops back to BIOS without detecting drives, or shuts off within 30 seconds due to overheating. If you smell burning, see smoke, or notice swollen capacitors on a motherboard, power off immediately and have it inspected. Consider replacing rather than repairing if your motherboard is an older socket with bent CPU pins, has a failed BIOS chip that will not flash, or costs more to replace than a modern equivalent. For example, a replacement LGA1151 board in the $150-$250 range may not be worth it if you are already planning a move to a newer platform that supports DDR5 and PCIe 4.0/5.0.

FAQ

What key do I press to enter BIOS on a new gaming PC?

Most ATX gaming motherboards use Delete. Tap it repeatedly as soon as you press power. Some prebuilt and laptop-derived boards use F2, F12, or Esc. If Windows loads too fast, disable Fast Startup in Windows or hold Shift while clicking Restart to get to Advanced Startup, then choose UEFI Firmware Settings.

Should I enable XMP if my RAM is already showing the right speed?

Yes, if your kit is rated for an XMP speed and XMP is disabled, you are not running at rated speed. After enabling Profile 1, confirm the frequency shows the advertised number like 3200 MHz. If the system fails to boot with XMP on, your motherboard or CPU memory controller may not support that speed – try the next lower profile or manually set 2933 or 3000 MHz at 1.35V.

Why does my new PC boot straight to BIOS and not Windows?

This usually means no bootable drive was found or boot order is wrong. Check that Windows Boot Manager appears in Boot Priority. If you just built the PC and have not installed Windows yet, that is normal – insert your Windows installer USB and set it as the first boot device.

Is it safe to use default fan settings?

Default fan settings are safe but often loud or overly conservative. They typically run fans at 50-70% at idle, which is unnecessary. Creating a custom Smart Fan curve is safe as long as you keep 100% speed set to trigger by 80-85 degrees Celsius, so the system can cool itself under gaming loads that draw 150-300 watts from the CPU and GPU combined.