I currently use my pc for work and its on for a good 12 hours a day continuously. My work involves running several programs but cpu and ram utilization is never that high (perhaps maybe around the 25-30% mark). Anyway, with my rig being on this much can I effectively mine cryptocoins for profit?

My PC spec is as follows:-

Intel Sandybridge i5 2500k
16gb ddr3 ram
500gb ssd
Geforce 660gtx 3gb

Given my above spec, whats best for me to mine? Is my gfx card (being nvidia) not suitable for gpu mining? Kinda late to the game but was wondering if I can make use of my pc when its idle or being underutilized. Any ideas? thanks in advance!