Like most manufacturers, Dell offers a specific way to restore its computers to a previous BIOS. Restoring a previous version of the BIOS is needed if the upgrade was not installed properly. You may also want to downgrade your BIOS if you notice hardware or software issues with your current BIOS. Dell provides you with several BIOS versions, depending on your needs.
Locate the current version number of your BIOS. Reboot your Dell computer. Press and hold "F2" key during start-up to access the BIOS menu. The current version of your BIOS is listed in the first screen that loads. It typically starts with the letter "A." Write this down on a piece of paper.
Navigate to the Dell website and locate the support page for BIOS versions. Choose a previous BIOS version from the list. Click the link to download the correct update.
Double-click to expand the instructions. Follow the instructions listed. These instructions will differ from one update to another. Depending on the version you have chosen to download, you will be prompted to use a floppy disk or another external storage device to download the BIOS. Insert the media as instructed and complete the download.
Reboot your computer. Make sure that that your BIOS media is still inserted. This will force your Dell computer to boot from the BIOS media. This also will initiate the installation of the previous BIOS.
Wait as Dell restores your BIOS to a previous version. Restart the computer if prompted.