Then i did virus scan on windows scan and it found lot of threats. Then how in the world do you protect yourself when googling things then? I mean are you suppose to inspect every single site you want to visit? So imagine you looking for cooking recipes and found a bunch of sites... you have to make sure its a cooking recipe site?
I don't understand why you've made it such a big deal. A computer that does not have a firewall protection is more vulnerable to be compromised. Just turn on your anti-virus, it will detect malicious sites and files. It's not recommended to keep bitcoins in such computer that connects to the internet either way.
You said you have a hardware wallet? What stops you from using it?