Do not turn off your computer or disconnect from the power source while updating the BIOS as this could harm your computer. During the update, your computer will restart and you may briefly see a black screen.

Before updating, please read the installation instructions and important information noted below.

Dell OptiPlex 990 System BIOS

Restart required AUTO INSTALLED This file was automatically installed as part of a recent update. If you are experiencing any issues, you can manually download and reinstall.
This package provides the Dell System BIOS update and is supported on Dell OptiPlex 990 systems running Windows and DOS operating systems. This update fixes the issue where Dell Diagnostics does not detect the thermal sensor.
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Fixes & Enhancements

Fixes:
- This update fixes the issue where Dell Diagnostics does not detect the thermal sensor.

Enhancements:
- Not Applicable.
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Version

A10, A10

Release date

08 Dec 2011

Download Type

System BIOS

Category

BIOS

Importance

Recommended
Dell Technologies recommends applying this update during your next scheduled update cycle. The update contains changes to maintain overall system health. It ensures that the system software remains current and compatible with other system modules (firmware, BIOS, drivers, and software) and may include other new features.
Available formats View Important Information

File Format: Flash BIOS executable
File Name: O990-A10.exe
File Size: 5.46 MB
This is a large file. Depending on your connection speed, it may take some time to download.
Format Description:
This file format consists of a BIOS-executable file. To use it, download the file and copy it to a DOS-bootable USB flash drive, then boot the system to the USB flash drive and run the program.
To ensure the integrity of your download, please verify the checksum value.
MD5:
2c1462fcef3ad3d8c7b830003d45cf37
SHA1:
1b07a6e17be9e1a19b4b0fa400b5fc38135ba7be
SHA-256:
Not available

By downloading, you accept the terms of the Dell Software License Agreement.

Additional details

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1. If the A04 or an earlier version of the BIOS is currently installed on your system, you must first update to A05 version of the BIOS and then flash to the latest A-rev BIOS.
2. If the A05, A06, A07, A08, or A09 version of the BIOS is currently installed on your system, you must first update the BIOS to A10 version and then flash to the latest A-rev BIOS.
Dell Optiplex 990
Updating the BIOS through Windows

1. Click Download File to download the file.
2. When the File Download window appears, click Save to save the file to your hard drive.
3. Browse to the location where you downloaded the file and double-click the new file.
The system automatically restarts and updates BIOS during the system startup screen. After the BIOS update is complete, the system reboots again.

Updating the BIOS from a DOS environment (Non-Windows users)

1. Copy the downloaded file to a bootable DOS USB key.
2. Power on the system.
3. At the DELL logo screen, press F12 to access the boot menu.
4. Select USB Storage Device and boot to the DOS prompt.
5. Run the file by typing the file name.
The system automatically restarts and updates BIOS during the system startup screen. After the BIOS update is complete, the system reboots again.


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Note 1: You will need to provide a bootable DOS USB key. This executable file does not create the DOS system files.
Note 2: Ensure that you suspend BitLocker encryption before updating BIOS on a BitLocker-enabled system. If you do not enable BitLocker on your system you can ignore this step.

Need help with BIOS issues?

Find a solution in Dell's BIOS troubleshooting and usage guide.

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