100% disk usage during antivirus scan

Yes, antivirus is responsible for most of the usage.  

 

I am using a Dell laptop. 

Whenever there is a 100% disk usage, everything becomes slow but still responsive. When I use side scrolling or zooming using touch pad, it just hangs up for 3 or 4 seconds and then scrolls or zooms.

But on my other HP laptop, even if there is 100% disk usage, there is no effect on its performance. Everything works well as if no scan is running.

Hi Kapil,

Thank you for keeping us updated.

I would suggest you to perform clean boot and check the status since this could also be due to any third party software conflict.

Step 1: To help troubleshoot error messages and other issues, you can start Windows by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.

Placing your system in Clean Boot state helps in identifying if any third party applications or startup items are causing the issue. You need to follow the steps from the article mentioned below to perform a Clean Boot.

How to perform a clean boot in Windows     

     

Note: Refer "How to reset the computer to start normally after clean boot troubleshooting" to reset the computer to start as normal after troubleshooting.

Step 2: If the behavior is same, disable the security software and check.

Important: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.

Please feel free to reply in case you face any other issues with Windows in future.

Being able to scroll doesn't require the disk unless you're very dangerously low on memory already.  It's like a car, there's many parts that have to all work together to perform the best.

Anyway, if it's stuttering and lagging when you scroll, and you're not very low on memory, then it's quite likely the CPU is the one causing the bottleneck (probably the deep-scanning of every file by the antivirus, rather than the actual disk activity itself).

For one example, you could right-click the process of the antivirus (on the details tab) and change the priority to low.  Then no matter how aggressive the antivirus gets, it's still lower on priority than the stuff you're doing (scrolling, using the PC, whatever).

And again if your memory is >80% used or so, that could also be a problem.  Then Windows has to start taking things out of memory and putting them on the disk temporarily to make more memory available.  The CPU has to do all that work, and the harddrive (which was already busy opening files for the antivirus to scan) now has to also go save the paging file (temporary memory file).  And now every part of the machine is busy, only causing it to get even worse, so the problems compound until something finishes or the system locks up entirely.  The OS tries to prevent this and usually does a good job.

PS. If you want my personal and professional opinion -- what I tell paying clients, family, friends -- I would recommend removing McAffee and just use the built-in Windows Defender.  It's free, never requires a subscription or renewals, gets fresh virus definitions multiple times per day, and is designed by definition to work better with Windows.  It even has early-launch malware detection to prevent boot viruses.  There's no reason to use a bloated, slower, and costlier program.  Again that's my two cents, if you are satisfied and love your service, I won't tell you it's bad. Just not as highly tuned as the original factory parts :)

I also want to remove McAfee. I am just waiting for its subscription to end.  :P  :)

It does not detect some threats. Once I scanned my Pen drive using McAfee it said "No Threats Found" then I scanned same pen derive using Avast, it detected Malware. :o

I can't change its priority. It is showing "Access is denied"

If you have more than one antivirus product installed they can conflict (Defender will turn itself off if it sees another, but I don't know if McAffee and Avast do the same).  Typically it just makes your system freeze and lock up, but they can actually conflict and destroy files, so just keep that in mind and make sure you remove all but 1 antivirus program (the one you want to use).

Anyway, on the access denied -- that is either because:

1. You are not using Task Manager as an administrator.  The easiest way to ensure you are is to search for Task Manager, right-click the search result and choose "Run as admin."
   
   or
   
   
   
2. The antivirus program is running under another security context that prohibits user-level changes to the priority.

I have already tried it by running as an administrator. It still show Access denied.

Is there any other way to change its priority?

Yes, I have experienced having two antivirus program in one OS. In that case neither work properly.

So, I use only one antivirus in one system. I have McAfee in one laptop and Avast in the

other.

Hi Kapil,

Thank you for keeping us updated.

• Did you try the suggestions provided earlier in this thread?

Since this behavior can be caused due to any third party software conflict, please perform clean boot and let us know the status. We'll be happy to assist you further.

Helo Kapil653,

I have the exact same problem you have. I have a HP computer, Windows 10 and Mcafee Antivirus. Have you found any solution to your problem? It would be very useful for me to know.


Thanks in advance,

Laura.

PS: Sorry for my english, it is not my mother tongue.