# First boot checklist: from bare parts to a Windows install

> A safe assembly and first-power-on order, the firmware settings that must be right, and the failures that happen on day one.

**Tested on**

- Build: 26300.9457
- Edition: Pro (26H2)
- Architecture: x64
- Evidence: E1
- Verified: 2026-10-29

## The short answer

Build outside the case first, power on with the minimum set, then add parts one at a time. The point is not superstition — it is that a fault with nine components installed has nine suspects, and a fault with three has three.

Minimum boot set: **CPU + cooler + one RAM stick + PSU + board**, with the GPU only if the CPU has no integrated graphics.

## Before you power on

1. **RAM in the right slots** — check the board manual for the single-stick and dual-stick positions (often A2/B2).
2. **CPU cooler mounted with even pressure** and its fan header connected to `CPU_FAN`, not `SYS_FAN`.
3. **EPS/ATX power** — 24-pin fully seated, 8-pin CPU power connected (some boards need both 8-pin and 4-pin under load).
4. **No stray standoffs** touching the board's underside.
5. **Front-panel headers** — at minimum the power switch; you can diagnose the rest later.
6. **GPU seated with the latch closed** and its power connectors from separate cables where possible.

```text
POST order that matters:
power switch -> firmware splash -> memory training (can take 30-120 s on first boot)
-> "no bootable device" (expected with no OS) -> install media
```

First boot on a new board can take **longer than usual** because memory training runs. A black screen for 60–90 seconds with fans spinning is not necessarily a failure.

## Firmware settings to set before installing Windows

| Setting | Value | Why |
|---|---|---|
| Boot mode | UEFI (CSM off) | required for Secure Boot and Windows 11 |
| Secure Boot | enabled (setup mode OK) | Windows 11 requirement |
| fTPM / PTT | enabled | TPM 2.0 |
| SATA mode | AHCI / RAID as intended | changing later breaks boot |
| Resizable BAR | enabled if supported | GPU memory access |
| Fast Boot | off during build | makes troubleshooting possible |
| XMP/EXPO | off for the first install | isolate stability |
| Fan profile | normal/standard | not silent during first install |

Then install Windows from official media and only afterwards tune memory profiles — one variable at a time.

> **Caution: Disable Fast Boot until the machine is stable**
>
> Fast Boot skips POST devices and can make a failing component invisible. Keep it off until the build has survived a week of use, then decide whether you want it.

## First-boot failures, ranked by frequency

| Symptom | First thing to check |
|---|---|
| No POST, no fans | PSU switch, 24-pin, front-panel power header |
| Fans spin, no display | RAM seating, GPU power, monitor input |
| Beeps / debug LED on RAM | reseat, one stick in slot A2 |
| Boots to BIOS only | boot order, CSM, install media |
| Installs, then boot loops | storage mode changed, or Secure Boot vs unsigned driver |
| Blue screen during install | RAM instability (XMP), or bad install media |
| USB keyboard dead in setup | legacy USB / XHCI handoff setting |

Debug LEDs (CPU/DRAM/VGA/BOOT) are the single most useful feature on a modern board — read which one stays lit before swapping parts.

## First Windows boot

1. Complete OOBE, then **run Windows Update** until it stops finding drivers.
2. Confirm device manager has no unknown devices.
3. Verify TPM and Secure Boot from inside Windows:

```powershell
Get-Tpm | Select-Object TpmPresent,TpmReady,TpmEnabled
Confirm-SecureBootUEFI
Get-CimInstance Win32_ComputerSystem | Select-Object Manufacturer,Model,TotalPhysicalMemory
```

4. Check storage health and that the disk is in the expected mode (`Get-PhysicalDisk`).
5. Only then install the GPU driver package, and re-check after the next Windows Update.

## What to write down

- Board model + BIOS version.
- RAM kit part number and the slots used.
- Which SATA/M.2 ports are populated (lane sharing!).
- The exact Windows build (`winver`).
- Anything you changed in firmware.

Six months later this note is worth more than the receipt.

## Related

- [UEFI settings that matter](https://windows.homes/en/hardware/build/uefi-settings/)
- [PSU sizing](https://windows.homes/en/hardware/build/psu/)
- [Hardware requirements by OS version](https://windows.homes/en/hardware/buy/os-hardware-matrix/)

## Lab boundary

E1. The boot sequence and firmware requirements are documented by Microsoft and board vendors. The lab builds Windows in VMs with OVMF, so physical assembly was not reproduced.

## Sources

- [Microsoft Learn — Minimum hardware requirements](https://learn.microsoft.com/en-us/windows-hardware/design/minimum/minimum-hardware-requirements-overview)
- [Microsoft Learn — Windows Setup command-line options](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-setup-command-line-options)
- [Microsoft Learn — OEM Secure Boot](https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/oem-secure-boot)

---

Source: https://windows.homes/en/hardware/build/first-boot/