You know what's best for you, But I have a retired friend still browsing with a 486! He points out that he only uses it for wordprocessing and only goes to trusted sites, and doesn't have an eMail address, so he uses a free viruskiller (or did, not sure if he can get one now)and he is an expert at formatting his harddrive and reinstalling.
I think I'm going to have to go the Linux route. Windows is becoming a treadmill of incompatibility and hardware requirement.