I like to dismantle mine and give it a good cleaning about every 6 months
After todays I believe Im gonna hit it like every 3 months. Wasnt to bad with only a few dust bunnies hoppin' around inside but it made a world of difference on how quiet the machine got after firing it back up.
About messed up though trying to get the CPU heat sink and fan back on. Screw driver slipped and raked across the board

, thank goodness I didnt hurt it.
Anyway, winters coming, and between the dust in the PCB's and humidity, better do it now and get ahead of the static games hurting it.