I have a pretty intense routine!
Virus scans twice a week, CCleaner once a week, various other scans once a week.
Only got 1 HDD so rarely defrag, usually once every couple of months unless I have been installing or downloading lots onto it. Its a big of a place to dump stuff I dont want clogging up my THREE SSDs
Every month I give the insides a good air dusting, the outside surfaces a wipe down and the fans a good clean. I also take out the graphics card and give that a good blowing out too.
Every 6 odd months I strip everything out, give the fans and radiators a deep clean with a vacuum (after totally removing them from the case of course).
Once a year I redo the thermal paste on my CPU, but only if the temps are starting to go up compared to my benchmark
Thats verging on OCD
you seriously redo the thermal paste?