As is stated in other threads:
Disable ALL automatic non-essential tasks
auto checking/updating for ALL programs
some of this is done using services.msc
some is done via the task scheduler
some of this is done in the programs
Disable auto power options
NEVER use sleep
disable wake timers, and auto hibernation
disable screen blanker, and screen auto off
Some people also recommend to have the hard drive and cpu always on and at full power.
Assessment processes: windows performs lots of performance assessments of the computer and then phones home.
Disable auto defrag, auto disk health, performance assessments,.... mostly in the task scheduler.
'Tis true most of us will not be aware of a lot of these activities. But late one Tuesday night the defragger started and slowness was the symptom. Never again will that happen to me.
I read about gamers spending lots of money and time overclocking and then not paying attention to these little changes that will reduce the process interactions and crashes.