Running any program on your computer will slow it down and antivirus software like Avast Premier Crack is no exception.
Whenever you run a scan, especially a thorough one, the program will use CPU cycles to get the job done. If you happen to be running other programs at the same time which, between them, are using a significant amount of processing power, then you may notice some slowdown.
Overall, the impact should be negligible, especially if you are using a modern computer, but some antivirus programs are bigger resource hogs than others. Fortunately, that is something we cover in our in-depth antivirus reviews.