BIOS Options Cannot Be Changed on Certain Latitudes

Summary: Information about certain Latitudes not being able to change BIOS settings.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Symptoms

The following BIOS settings cannot be changed.

  • Storage > RAID On > AHCI
  • Virtualization Support > Intel VT-d Enabled > Disabled

Affected Systems:

  • Latitude 3420
  • Latitude 3520

Cause

The Intel RC setup value table must be reloaded.

Resolution

Reset the Real-Time Clock

The following steps can be used to reset the Real-Time Clock (RTC):

  1. Shut the system down.
  2. Plug in the AC adapter to the system and a power outlet.
  3. Press and hold the power button for 25 seconds.
Note: You see the power light flash, 2 white, and then 4 white.

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Affected Products

Latitude 3420, Latitude 3520
Article Properties
Article Number: 000372620
Article Type: Solution
Last Modified: 23 Sep 2025
Version:  1
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