I want to use my remote control to turn on my pc but it doesn't work. I can turn off my pc with the remote control. How can I also use my remote control to turn on my pc? Is this a missing bios killswitch or a os setup?
It's a hardware thing. The BIOS/Motherboard generally must support Wake-On-USB (assuming the IR receiver is a USB device), and the receiver must know to send the wake-up signal when it sees the power button being pressed.
Your best bet for finding this and getting it working easily is to find a motherboard which comes with a remote for this purpose. Asus has made motherboard + remote combos that were targeted at media center PCs that explicitly support this.