Can I put on some work my 2 computers ?

As title says I have 2 computers sitting in my home. I was wondering if there are some ways to put them working something passively? Especially when I am on my job they are being totally useless, in that period of time if I could make them do something that will make even least amount of $ would be great.

Any working tips?

That's possible, it involves methods and using bots