Either

a. not Windows (which is offtopic given Avast targeted Windows with lip service for MacOS/Linux/Docker) [0]

b. or Windows (in which case they DID run antivirus via Windows Defender)

[0] https://businesshelp.avast.com/Content/Products/SysReqs/SysR...

Windows on a gaming PC, Mac for Work and Ubuntu for the daily driver. I’m going to be replacing the Windows PC with steam deck once I scrounge the cash for it.