If we're specifically talking about supporting the BTC network with running a computer 24/7, installing nodes would just be the support that you could do. According to the
Bitcoin.org website.
If you were to use your PC to do other stuff like use Bitcoin as a currency, spread the news about Bitcoin, improve the Bitcoin Software, donate, etc. Just like in the support page, I think that's just it.
This may not
support Bitcoin directly, but it supports yourself (if you do trading).
If you are going to let software like
Gunbot to trade for you, that's a software you could run on your PC 24/7 instead on a VPS which would cost you additional money.