On Thu, 28 Dec 2017 22:47:31 +0800, "Mr. Man-wai Chang" wrote:

On 28/12/2017 14:34, Optimist wrote:
Why is it that very often the PC keeps awake? The monitor switches off OK, but whereas sometimes
the PC's light blinks indicating sleep, very often it just keeps going, sometimes for more than 24
hours.

I know W10 has to do housekeeping tasks like creating backups of the operating system but surely
these tasks can't take all that time?
...

Did you turn off Defrag? And don't forget about Window$ Defender might
do some background scanning when the PC is idle....

I haven't done anything to Defrag. Windows Defender not active as Kaspersky is running.