free anti virus program

some time ago i asked about what were some free antivirus programs. and you pointed me to avast, and a few others.
i did not jot then down and i did have them in a folder on a thumb drive, but i put that thumb into my netgear modem to use as a place to put these types of files and that modem ruined that thumb drive, so i lost all those files.

also i was trying to get my fingerprint scanner to work and the files and program some here had me install caused my pc to fail, so i had to do a reset, so then i installed the free antivirus program that comcast gives me for having comcast but that one made the pc slower and it messed up my passwords. yep every site i went to made me change my password. and the norton people did not have a fix for it, so i uninstalled norton and then setup windows security and defender for now.

so because i did not jot down the 3 or 4 free program that was told to me that windows works good with i have to now get them again, and yep i learned to not put another thumb stick into my modem or at least the one that does have all my backups on it.

at this time i do have ccleaner. but i have not yet put in avast or i think it was malwarebytes and some other program. so any input on the ones i need to be good for my win10 64bit enterprise. before i had to do a reset i had the pro version. so is pro better than enterprise? if not how can i get up to the pro version again as well. thanks

it could be. i just went and installed norton security i got from comcast for now and will run that unless i hear different. but some of the research is telling me norton and defender work good together so i picke that. thanks jaycee