How to Downgrade BIOS
A computer's BIOS, or Basic Input/Output System, is responsible for providing the framework that allows the system's hardware and software to successfully communicate with each other. There are times that downgrading your system's BIOS to an earlier version is necessary to restore stability or enable optimal hardware support. Flashing the BIOS to a prior version is similar to a normal BIOS update.
Determine your current version of BIOS by clicking first on the Windows logo in the bottom left of your screen. In Windows XP, open the "Run" box, while users of Vista and Windows 7 can type directly into the search bar. Type "msinfo32" and press "Enter" to bring up a page displaying your system information. Make a note of all the text beside "BIOS Version."
Navigate to the website which hosts versions of your BIOS. You can also navigate to the computer manufacturer's website or the website of your motherboard's manufacturer. The manufacturer's name is listed alongside your BIOS version from the previous step.
Click on the link which will take you to the company's support page. Follow the page's instructions to get to its downloads location. Examine the list of available BIOS packages and select the file that you would like downgrade to. Download the older version of the BIOS and any supporting documentation.
Read all supporting documentation that accompanied your BIOS file. If it instructs you to perform any other particular patches or preparation before downgrading versions, follow its instructions exactly.
Flash your BIOS to the earlier version. In most newer computers, this will simply involve running the file that you downloaded from your manufacturer's website and allowing the executable file to handle the downgrade automatically. For some older computers, more elaborate steps may be required. In these cases, follow the instructions as outlined in the accompanying documentation.
Tips & Warnings
- Never remove your computer from its external power source while flashing its system BIOS.