Boot scan, the differences?

[Rixuel]

Hello, I've a question.

What is the differences between doing a normal computer scan and a boot scan?
When to do a boot scan?

[Pondus]

When to do a boot scan?

when the normal scan have problems removing malware...

Avast Antivirus offers a "boot time" virus scan of your PC. This allows the antivirus engine to scan all of the files on your hard drive before any other programs load - useful in cases where you have an infection which cannot be cleaned because the "file is in use"

http://www.digitalred.com/avast-boot-time.php

The boot-time scanner is an expert feature, and was designed to be used when there’s something bad going on on the system. And in these cases, I’d say that having to actually select the actions manually is a small price to pay.

https://blog.avast.com/2010/02/04/v5-bts-auto-actions/

[Rixuel]

Thank you very much