More often for some depending on if you have pets,
My sister-in-law brought me her desktop PC when she thought it was broke. It wouldn't start or anything. I took the cover off.
She'd had it about 5 years or more.
She also has 3 (maybe four cats) and a dog.
I could have made a whole other cat from the hair I found inside the tower. Everything was coated, matted, and covered with it.
If that wasn't bad enough, I grabbed my can of air.....
I don't know what I was thinking.
I really don't.
The first blast was like...it was like the feline version of Raiders of the Lost Ark. You know at the end when all that stuff comes swirling out of the ark like a nightmare tornado? Picture it with nothing but cat hair, dust, and dander. And I'm the guy standing right over it with his face practically in it.
After cursing the cats and myself I went and got my industrial back-pack vacuum cleaner.
I will never own a cat.