I want suggestions for a good free antivirus (Avast/Avira....) for my HP Probook (Win 10 Pro) laptop. For the last 7-8 years I have been using Linux. So don't have much practical knowledge about current antiviruses and their effectiveness/efficiency.
For a home user I would simply recommend you to use the in built Windows Defender. The reason being it just comes along with a simply built user interface, without extra bunch of bloatware, such as cleaner, driver updater etc that most modern free antiviruses bring. One great feature is also the ability to get offline updates.
Besides, this makes it light with reference to resource consumption. The detection rate is very good and compares to other premium antivirus softwares well.
For a corporate office/ business use , something like Kaspersky or Bitdefender comes in handy, because in corporate environments there is need for strict monitoring of servers, network resources etc so these premium antivirus softwares ate suited for this (Note: Some of these are free with some features subtracted, but you still se the main AV functionality).
Glad to hear from a Linux guy. Many people would prefer just using the Windows defender that comes by default along with Malwarebytes Anti-malware as a second layer of defense. I recommend you too this if you have a laptop with good specs (I hadn't searched about your laptop), cause Defender reportedly has a considerable impact on the performance (like high RAM/Disk/CPU usage). If you would like to try something more, then consider the following alternatives:
BitDefender free has less impact and requires minimal/completely no maintenance after installation. This might be suitable if you dislike wasting your time hanging around the AV. Furthermore, BitDefender offers top notch protection this day.
Secondly, Avira offers a top notch protection too. It reportedly has a little impact on the performance though the company says it doesn't.
Finally, Avast, the most popular AV, is a choice too. But, it has a low detection score than the formers.
Besides, a good Anti-malware software like Malwarebytes Anti-malware is also recommend.
For more detailed comparisons, visit AV-Comparatives: An independent AV benchmarking organizations that is trusted by many.
Hope this helps.