Hello Andy.
We regret the inconvenience.
Are you using AVG AntiVirus free? We'd request you to repair AVG and check if the issue is resolved.
Each day when I switch on my W10 desktop I see 100% disk usages for over an hour.
looking the the details on task manager it is AVGSvc.exe and aswengsrv.exe doing the vast majority of I/O operations
Hello Andy.
We regret the inconvenience.
Are you using AVG AntiVirus free? We'd request you to repair AVG and check if the issue is resolved.