How do I run a full scan using Windows Defender?
Hi, everyone. Leo, Notenboom here for
askleo.com.
It's not uncommon for us to suggest that you run a full anti malware scan
if you are, are encountering issues with your system. If you suspect that there
might be malicious software of some sort on your machine.
But what does that mean?
If you're running what I generally
recommend people run these days, and that is Windows Defender or
Microsoft Security or whatever they're calling it this week?
Let me show you.
So what we're doing this is Windows 10.
I'm going to bring up the Settings app.
I'm right clicking on Start and in the alternate Start menu,
click on Settings and hitting first of all things, updates and Security because one
of the first things I want you to do is check for updates.
Now you'll notice it says last checked
today at 202, which is what 30 minutes ago, according to my clock.
So I'm going to go ahead and hit check for updates.
And yes, I know I can't run Windows Eleven.
That's okay.
And we may or may not get an update for Windows Defender.
Now, in this particular case, we did not.
I'm getting some other kind of an update, which I am going to let install.
I'm not going to take the 21 H Two update just yet because once this install has
completed, I'm going to check for updates again, and it may seem counterintuitive.
Hopefully the example will prove me right.
But what I have seen is that every once
in a while, as soon as you click check for updates,
there is in fact, an update available, and it's an update to the Windows Defender
definition of what malware exists in the world.
And it's that definition that you always want to be as up to date as possible.
Checking for updates again.
Okay, so I'm as up to date as I can be without 21 H Two being installed.
I do recommend that you run through this process before you run a full scan,
because this is how you make sure that you have the latest virus definitions,
and in fact, you have the latest Windows Defender tool as well.
So at this point I'm going to go ahead and close the Settings app.
I'm going to click on the Windows Security icon, which brings up Windows Security.
We'll then click on Virus and Threat
protection, and you can see here that it says Quick scan.
That's not what we want.
That's what's been happening automatically for some time.
What we want instead is to click on Scan options and then click on full Scan.
Full scan checks.
Basically everything on your machine.
I'm going to go ahead and get that started
because that's going to take some time now.
While it's running, the difference between
a quick scan and a full scan is actually fairly simple.
A quick scan focuses on those things that are most likely to be compromised,
the places where malware usually hides in Windows itself,
in the programs installed on your machine, and probably a bunch of other areas
that we can't even think of that we don't even know about.
But the bottom line is that by definition,
it's making a decision about what is and is not most likely to be infected
and only scanning those areas because it's quicker.
It takes less time.
A full scan doesn't make those assumptions.
It's going to scan all of the files on my machine.
And when it's done, let me know what it finds.
Now, as you can see,
this scan is going to take on the order of, it claims, five minutes or more.
That number will vary dramatically based on your machine.
Two or three things factor into play how fast your machine is in terms of its
processing speed plays a little bit of a role.
How fast your hard disk is probably plays
a bigger role, because that's what's being exercised the most here.
And then, of course, how big your hard disk is,
how much is on it? Not really how big the disk itself is, but how much data,
how many files, how much space is being taken up by all of the things that are
stored on your hard disk? If you've got a lot of stuff, well,
this scan is going to scan a lot of stuff, which means it's going to take longer
again than a quick scan, or that a machine that doesn't have as much stored on it.
So I'm not going to run this to completion, but I at least wanted you
to see exactly what it takes to run a scan.
Now, there are a couple of caveats here. One.
Like I said, a full scan can take a really long time.
You can continue to use your computer.
It'll probably a little pokey again, that's going to depend on your computer,
but it will probably take a little bit more time to do some things because it's
working hard on this full scan that you've got going in the background.
The other caveat.
And this is the one that a lot of people are uncomfortable with.
A full scan is no guarantee
there may still be malware on this
machine, even if the antimalware software says there isn't.
And that's true for any anti malware software you happen to use.
Be it Windows Defender,
be it some other tool, a third party tool, a free tool, a tool you've paid for.
It doesn't matter.
Every antimalware tool misses something.
There's a variety of reasons for that,
but the bottom line for this discussion is that it's reality.
So you still need to keep your guard up.
Can't let your guard down just because
your malware tool tells you it didn't find anything.
All it's telling you is it didn't find anything.
It's not telling you that there isn't anything there.
So carry on.
Use your machine with the usual common sense and safety steps that you already
know how to do to prevent your machine from becoming infected and keep an eye out
for behavior that indicates that it might for updates.
For related links for comments and more, visit
askleo.com/139376
I'm Leo Notenboom and this this is Askleo.com. Thanks for watching.