How to Remove a Virus from The BIOS

If you are having difficulty in starting your computer, it could most certainly be a virus; but where is it? It is not invincible that it lies within the BIOS. To remove a virus from the BIOS, you need to follow a few steps.

First though, make certain it’s a virus, then a virus in your BIOS. If you are unsure, start off by reviewing the following articles:

How to Fix a Computer

Here’s How to Run Windows 7 Startup Repair

Windows 7 Keeps Booting in Safe Mode [SOLVED]

Repair Windows 7 Master Boot Record

Check For Virus

If you have done most of the above, or certain it is a virus that is halting your computer, then the best way to discover where the virus is located is to do a few additional troubleshooting steps.

Boot to a antivirus rescue CD and scan your computer. I recommend using BitDefender; it’s free to anyone and simple to create. Follow these instructions for details: Using BitDefender Rescue CD to Scan For Viruses

Now, if you boot your computer and have the same issue, we have narrowed it down to a virus in the boot sector of your disk (HDD), or in the BIOS. The next instructional set will determine if the virus is in the boot sector (of your HDD) or in the BIOS.

1. Power off computer
2. Disconnect connection and power to hard disk drive
1. For laptops, remove the hard drive
3. Try booting from your Windows system disc as a test (DO NOT FOLLOW THROUGH)

If the recovery or install process starts, your virus is most likely is in the boot sector of your HDD. If not, then it’s in your BIOS.

Virus in Boot Sector

If the virus appears to be in the HDD boot sector, you can use GMER. Find a download link and information here: http://www.gmer.net/#files

Typically, this is executed from the system drive (C:), so not certain if it will work properly from a optical disc (CD/DVD).

Virus in BIOS

You can attack a virus in a couple ways. First, would be to load the BIOS defaults by purging the power. This process would require you to also remove the CMOS battery. However, it is password coded. The unfortunate thing about this is it hard-coded in the CMOS and does not leave even with power removed. You would need to obtain the master reset code to follow this process.

Flash the BIOS

Here are the instructions to flash your BIOS…

1. Contact your BIOS/Computer/mobo manufacturer for specific flash instructions
2. Download BIOS file from a different computer and write it to an optical disc (CD/DVD) using the create bootable disc option- your CD must be bootable for this to work
3. Open your computer side panel and disconnect any/all hard drive cables (not necessary to remove drive, just the connector and power cables) (leave computer open)
4. Put the CD into your infected computer’s optical drive and turn it on (you may need to turn it on first, place the disc in, and reboot using Ctrl+Alt+Del)
5. Boot to the CD disc (you may need to press F5, F12, or the ESC key to enter boot menu- look for a message at the bottom of your screen telling you such)
6. Once the flash disc loads, there may be a list of optional instructions; select the most appropriate, otherwise, let it run
7. DO NOT TURN POWER OFF TO COMPUTER WHEN THE BIOS UTILITY IS RUNNING
8. Allow the computer power to recycle, or follow instructions. Once complete, turn it off, reconnect drive cables, replace computer side panel, and turn on computer
9. Go through the entire process of completely repartition and format the drive

Additional Input

Last resort, contact a professional service, such as Malware Experts.

Hopefully, this article has provided you a means to remove a virus from the BIOS.