I'm patching my workstation regulary (1 security update is just waiting to be installed).
They also have antivirus installed (not avast! but still ).
I've also installed Firefox Portable on it (no admin rights required ) just to be sure.
We still have IE6 installed for some reason, probably because they use propertiary interface that runs inside browser.
At home, all systems are fully updated at all times and extreme caution is used when on the internet.
At the Senior Center ( where I am now ), I've installed a program called
Deep Freexze. The system restores itself to a safe controlled state each time the system is rebooted.
No record of any activity is ever saved longer than one session and is totally gone when rebooted. This includes any infection which might have occurred.