Kantwebefriends wrote:"In fact for people with very large investments I would say its worth having a dedicated device for doing banking/trading and nothing else."
We don't have very large investments but we do have an old laptop we don't use much. I suppose I could delete all the cookies, delete the email accounts and all the blog links, delete everything, in fact, bar the single browser, the virus protection software, and links for banks and so on. Might that be a wise move?
The safest option is to have a supported machine with all security patches applied. Old machines like Windows XP can be compromised by just connecting them to the internet, you dont even have to open a web browser.
The biggest source of infections are drive-by downloads delivered by the ad networks, blocking ads improves your online safety as much if not more than installing a virus scanner. The second biggest source is probably email.
So yes if you have an old unsupported machine, will be safer if you stop using it for other things but not completely safe, unfortunately theres no substitute for being fully patched.
Some people will say that a machine which is old enough will have such ancient security holes that nobody will be looking for them, unfortunately the figures don't back that idea up, that majority of computers being compromised are
due to vulnerabilities for which patches had been made available (but not installed) months or years earlier.
The big IT companies employ hundreds of highly paid security engineers to write and distribute all these security patches, which adds up to a significant drain on their profits, they don't do it for the fun of it!