Yes, DavidR, I do have all my data backed up. Twice at all times. And every week I put a third copy in a secure, off-site location. I can format and restore if I have to, but it’s a royal pain. The worst that could happen is that I lose one week’s work.
Still, a full mirror is expensive. Everything is a balancing act between cost, security, and convenience. Anti-virus software is a part - an important part - of the act, but certainly not the only part.