I am running a 2 machine setup at home. My main edit box and another far lower spce machine i use for interweb email and so on.
These standard rules are quite simple. -
# Never use your edit machine to surf the internet. The only exception is installing updates but otherwise keep it locked down tight. Even going to web based mail accounts can get you infected with Viral cookies and trackers.
# Keep it Simple) Dont install software you aint gonna use. This includes windows. After an install of Windows go and remove unessessary components such as those crappie games like solitare and other appz like windows messenger. They take up unnecessary space.
# Defrag. If you are busy with your machine and the hard drives are working overtime frequently then dedicate time at least once a month to defragment the drives. - Remeber to leave at leaast 15% free space on each drive otherwise it will sloooooooow right down and you wont be able to defrag anyway.
# Keep up to date with drivers and updates - it does make a diffrence.
# Dont leave the machine on unecessarily (ie pop out to the pub for a few hours).
I've found by following these rules my main machine has been running so sweetly.
DONT EVER USE windows movie maker unless you wanna use it to encode summat.