Using a browser isn’t the only way it would be connected to the internet though, I know for sure there are malware bots actively searching for network connected XP machines that can brick systems just for existing on a public network, and I wouldn’t be surprised if the same wasn’t the case for 7. Anti-virus can only do so much for you if you’re a victim of ransomware or some remote execution exploit found since EOL

Just please make sure it’s not internet connected if you value such things as your privacy, and bank accounts not being breached extremely easily. End of security support is no joke.