I have a confession
Still using XP. And 7. And Windows 98 (because it won't run anything else, cough industrial PC /cough)
Its a problem but if you glue the USB ports and only ever use pressed disks, basic security is fine.
It has antivirus and the ability to restore the OS if things go south.
Backup system: internal BIOS is password protected and can't be changed because I took the CMOS battery out to ensure no data retention.
Sure malware can mess with it but it fails in the "no longer boots" safe mode.
One sure fire way to ensure you never get 0wn3d is to use a really old PC and only use it with a bootable media burned to CD which in the event of a drive issue nukes and paves itself then reloads from the backup which is a <10 minute job.
All the user data is stored on write once read many (WORM) drive which writes the raw files directly to Flash then updates the file table to lock the sectors permanently.