Kaspersky is constantly rated at the top for pc security protection. I use it and it has kept my pc clean. I do not know if there is a free version. The company is headquartered in Russia. There have been reports (maybe fake news) that the Russian spy agencies are involved at Kaspersky causing fear that Kaspersky protected devices can be hacked by the Russian government. I still use Kaspersky anyway. I have no information on my computer that the Russian government would want.