I dont think any computer is fit to mine alone, unless you are using it to install the mining pool software etc.
This is definitely true nowadays - at least for SHA-256 coins such as Bitcoin, but it wasn't case before SHA-256 ASICs arrived in 2013. Someone even mined hundreds of bitcoins on an old Pentium 4 back in the early days of Bitcoin. And even up until 2013, people were using high-end gaming rigs with expensive GPUs to mine.