1 instance, 12 threads, one thread for each physical core, then open task manager, go to details, find the process and right click on it (you should be running cpuminer-aes-sse42.exe), then select set affinity, then make make sure every other thread is checked off, so for you 1 3 5 7 9 11 13 15 17 19 21 23 are checked off and 0 2 4 6 8 10 12 14 16 18 20 22 are NOT, you can also set the propriety to low, that will make the system more responsive and usable during mining, idk why im helping i wanna keep the hash rate low but whatever good luck