Had used KIS for the last 3 years and was having a half-dozen minor issues I knew/suspected to be caused by KIS. Replaced KIS with Bitdefender and all of those issues resolved. FWIW....
Bitdefender is the product of Romanian computer software company SOFTWIN. For now, I'm happy to have my "KIS issues" resolved. If there are issues with Bitdefender, will cope... none so far.
Scat, Bitdefender is the best, but its almost too aggressive. You will probably find you'll need to tweak it some depending on what you do. Good stuff though.
Bitdefender is the best free antivirus for home users http://www.bitdefender.com/solutions/free.html Tests of antivirus software https://www.av-comparatives.org/
I had to remove kaspersky. It was causing constant glitches and brought my new alienware pc to a crawl at times. I installed trend micro - I suspect it is also hogging resources but at least seems stable.