In general Avast Antivirus 2015 is very light and doesn’t slow your computer notably. But does it slow down the boot time of your Windows? We have performed a simple performance test and gathered some interesting data.

First of all we started by removing Avast Free Antivirus 2015 using the Avast Uninstall Utility. Then we performed a random 10 boots into Windows and measured the boot time. Next we have downloaded and installed the latest version of Avast Free Antivirus and measured the boot time results for couple of days.

Results we got were quite shocking as the average boot time increased from 30 seconds to 60 seconds. So it basically doubled.

Test results are represented on the chart below.


By boot time we consider three areas

  1. Windows boot starting from the ‘Welcome’ loading screen which includes loading drivers and starting services
  2. User login as we have used Windows with single user and no password, so it was fully automatic and didn’t require any user action
  3. Desktop load which includes preparation of the desktop and load of the start-up programs

In the first day of installation the boot time was significantly higher (around 90 seconds). In the upcoming days the boot time dramatically decreased and oscillated between 40 and 100 seconds. But obviously the average time is still way above the default time when no Avast has been installed.

In the next performance test we will test the Avast Free Antivirus 2015 impact on the system speed and standard user actions like browsing the Internet, copying or deleting files.


For measuring the boot time we have used a free tool called BootRacer. We have tested Avast Free Antivirus 2015 (2015.10.2.2215) released on March 23, 2015. Test was performed on a Windows 7 Professional x64 computer with CPU Intel Q8300 @ 2.50GHz and 4 GB RAM.

Written by Paul B.

My name is Paul and I love Avast since the Home Edition v4.8 (2008). I am recommending it to all my friends, but I realized they don't know how to use it. So I started this site in order to help others getting maximum from this awesome antivirus. Feel free to contact me via Facebook, comments below or this form.

This article has 1 comments | Did we miss anything? Just let us know in the comments!

  1. 3ogdy Reply

    This is true even with the 2017 version. Se7en SP1 on Samsung SSD. The whole system is slowed down to a crawl. At least on the first day. Boot time is probably 3 times slower. CPU usage (FX8350) doesn’t want to go down to lower than 80%. Thanks to avast!. This thing is unbelievable. It’s run the compatibility scan and didn’t complain about Malwarebytes Premium.

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