What is the recommended action if a boot sector virus is suspected?

When a boot sector virus is suspected, rebooting from an external device and performing a scan is the recommended action. This approach is vital because a boot sector virus infects the master boot record (MBR) or the boot sector of a drive, making it active immediately when the system starts up. If you attempt to boot from the internal hard drive, the virus could activate again and hinder any attempts to remedy the situation.

By using an external device, such as a USB drive with trusted antivirus software, you can effectively bypass the internal hard drive, preventing the virus from executing. This allows for a clean environment to scan and eliminate the virus without interference.

The other actions do not address the core problem effectively. Rebooting from the internal hard drive could reactivate the virus, disabling security software would leave the system vulnerable, and restoring system files immediately may not remove the threat and could result in further complications if the virus remains active in the boot sector. Hence, scanning from an external device is the most effective and recommended action to dealing with a suspected boot sector virus.