How to Clean a Boot Sector With a Virus

A boot sector virus is a type of computer virus that places malicious code into the MBR (Master Boot Record). During startup, the boot virus is loaded into the computer's memory and will infect any uninfected drives that are accessed by the computer, such as other hard drives, removable media drives, and storage disks. Fortunately, removal of a boot sector virus can be done by downloading, installing, and running an antivirus program that includes a boot sector scanner. For the method below, you'll need a second computer with a motherboard that is compatible with the infected drive.

Things You'll Need

• Phillips-head screwdriver
• 2 computers

Instructions

1. Remove the infected hard drive from first computer. Unplug the power cable from the first computer, then use the Phillips-head screwdriver to remove the screws that hold the side panels on each computer. Unplug the power and data cables from the infected drive and then use the screwdriver to remove the screws that fasten the drive in place. Remove the infected hard drive from the first computer and set aside.

2. Download an antivirus program that includes an MBR (Master Boot Record) scanner onto the second computer. Double-click the downloaded file and install the antivirus program with the default settings and in the default directory. When the antivirus program has finished installing, click the "Finish" button.

3. Update the antivirus program so that the program contains the latest virus definitions. Restart the computer and allow the operating system and antivirus program to load.

4. Shut down the second computer and unplug the power cable.

5. Remove the screws that hold the side panel on the second computer with the screwdriver. Plug the infected hard drive into the second computer as a "Secondary" or "Slave" drive. The antivirus program will prevent the drives installed on the second computer from becoming infected with the boot sector virus.

6. Plug the power cable back into the second computer and turn it on. Allow the operating system and antivirus program to load completely.

7. Run a full scan on the infected hard drive with the antivirus program, ensuring that an MBR scan is run. The computer may need to be restarted to run the MBR scan from a command prompt. Once the scan is complete, your computer will continue loading the operating system.

8. Shut down the second computer and unplug the power cable. Remove the hard drive from the second computer and replace the side panel, fastening it into place with the Phillips screwdriver. Plug the power cable back into the second computer.

9. Install the hard drive back into the first computer and replace the side panel, fastening it in place with the Phillips screwdriver. Plug the power cable into the back of the first computer.

10. Turn on the first computer and allow it to boot up normally. If the MBR has been scanned and the boot sector virus has been cleaned, the computer will start up normally and the operating system will load.

Tips & Warnings

• Install an antivirus program on your computer to prevent recurring virus infection.

References

• TomsGuide: How To Clean Virus In Master Boot Sector
• MicrosoftSupport: Methods to Detect a Boot-Sector Virus