Dell Portable BIOS and Diagnostics Rev A34.120 — What It Is and Why It Matters

Dell’s Portable BIOS and Diagnostics (Rev A34.120) is a firmware-level troubleshooting package that lets technicians and advanced users diagnose, test, and update Dell systems outside the operating system. It’s provided as a bootable image (USB or ISO) and includes BIOS update utilities, hardware tests, and system information tools that help pinpoint problems with components like memory, storage, CPU, GPU, and system firmware.

4. Intel Management Engine (ME) 8.1 Update

Security-conscious IT departments will appreciate that A34 patches the Intel ME vulnerability CVE-2017-5705. Without this revision, a malicious actor with physical access could bypass BIOS passwords.

What You Need

Error Codes

Rev A34 120 outputs Dell-specific validation codes. For example:

Write down the 7-digit code and contact Dell ProSupport if under warranty.