Oh ok ta. I have no idea what it’s running. I hardly ever use it but it’s less than 5 years old.
Edit, just looked and it’s running windows 10. There’s a windows 10 updater thingy that’s up to date.
Strangely I’ve just had a pop up telling me my McAfee subscription has lapsed ( hence my original question ) and near the bottom it says Microsoft Defender Antivirus will be defending it!

Hey ho, I should’ve waited 24 hours!

Cheers.