Boot scans, also known as shoe scans, or pre-boot virus scans, are advanced tools that antimalware software uses to remove malware which may not have been detected by conventional scanning software. This type of scan can be configured to run at regular intervals or be invoked manually by the user when they suspect that their computer is infected. A lot of antivirus programs allow users to select the sensitivity of the boot scan, as well as what actions to take in the event that a threat is discovered.
The reason a boot scan is so efficient is that it allows the antimalware software to detect files that are used by the operating system. These types of files cannot be deleted because they are always being used by the OS and will return an Access Denied error when attempts are made to remove them. The boot scan will find these files and allow the antivirus software to eliminate them before the OS is able to begin using them.
The duration of a scan during boot will vary depending on several aspects, including the speed of the scan and the number of system files that are being scan. It also depends on whether the machine is in use during the scanning process. This type of scan can be more time-consuming than a typical anti-virus scan due to the thoroughness of the process.
