NVMe Support (AHCI/RAID) for Legacy Systems — Setup, Drivers, BIOS Mods & Troubleshooting (UEFI/MBR)

[andermaxpc]

This pinned topic is a practical starting point for NVMe / AHCI / RAID driver questions on older systems (legacy BIOS, early UEFI, Windows 7/8/10/11, and mixed MBR/GPT setups).

The goal: help you boot and run NVMe SSDs reliably, with or without BIOS modding, using the correct storage mode (AHCI/RAID), proper drivers, and correct boot configuration.

What we cover here (allowed topics)

1. NVMe boot on legacy platforms

   • Adding NVMe support to a motherboard BIOS/UEFI (where possible)
   • Using NVMe on systems that can’t boot NVMe (bootloader methods, secondary drive usage)
   • GPT vs MBR, UEFI vs Legacy/CSM, secure boot considerations

2. AHCI / RAID storage drivers & installation

   • “No drives found” during Windows setup (WinPE driver loading)
   • Intel RST / VMD / RAID mode vs pure AHCI
   • AMD RAID vs AHCI (where applicable)
   • Installing Windows on NVMe when BIOS/UEFI is picky or incomplete

3. Troubleshooting common failures

   • NVMe not detected in BIOS/UEFI, detected in OS only, or intermittent detection
   • Boot loops after cloning / imaging
   • 0x7B INACCESSIBLE_BOOT_DEVICE, 0xc000000e, “boot device not found”
   • Slow boots, freezes, random disconnects (driver/firmware/power/adapter issues)

4. Adapters, compatibility, and real-world limitations

   • M.2-to-PCIe adapters and lane wiring (x1/x4/x16 slot behavior)
   • PCIe generation negotiation issues on old chipsets
   • BIOS size/structure limits that affect modding outcomes
   • NVMe SSD firmware quirks, power management, and ASPM-related issues

What is NOT allowed here

• Any request or instructions aimed at bypassing security policies, ownership locks, or unauthorized access
• Malware, stealth persistence, or “hide/disable security features” requests
• Anything illegal or clearly non-legitimate

Before you create a new topic, please provide (copy/paste checklist)
A) Hardware / platform

• Motherboard model + exact revision (if known)
• CPU model
• Chipset (if known)
• BIOS/UEFI vendor + version/date
• Boot mode currently used: UEFI / Legacy / CSM
• Storage mode: AHCI / RAID / Intel RST / VMD (if present)

B) Drive + adapter details

• NVMe SSD brand + model + capacity
• NVMe firmware version (if available)
• If using adapter: M.2-to-PCIe adapter model + which slot used (x16/x4/x1)

C) Operating system + install method

• OS version (Windows 7/8/10/11 / Linux distro)
• Clean install vs clone vs migration
• If Windows setup: what media (USB), and at what step the issue occurs

D) The exact problem

• What exactly happens (error text, behavior)
• When it started (after BIOS update, driver change, clone, new SSD, etc.)
• What you already tried (so we don’t repeat basics)

E) Evidence (highly recommended)

• Photos/screenshots of BIOS storage settings and boot page
• Disk Management screenshot (if visible in OS)
• Setup screen screenshot if “no drives found”
• Event Viewer / logs if you have them

Quick guidance (most common fixes)

• If Windows Setup can’t see the drive: load the correct storage driver (RST/VMD/RAID) OR switch to AHCI when possible.
• If you cloned from SATA to NVMe and it won’t boot: check GPT/UEFI alignment and ensure the EFI partition exists and is used.
• If the drive is missing in BIOS but visible in OS: your platform likely can’t boot NVMe natively without a proper UEFI NVMe DXE / boot method.
• If detection is random: check adapter quality, slot lanes, BIOS PCIe settings, and power management.

If you’re unsure where to start:
Create a new topic and fill the checklist above. The more exact your board/BIOS mode/driver mode details are, the faster you’ll get a correct answer.