Halo isn't very graphics intensive and most computers can run it smoothly, especially after being gameboosted. I've personally never used a HDPVR but I hear that streaming with it is kind of laggy, not too sure though. But yeah, basically any computer with 2gb+ RAM should be able to handle it, 4gb+ if you want to be sure. The processor/graphics card won't really matter in your price bracket, and neither should be required to be that good if it's only halo you're streaming. NOTE: I interpreted this as if you were streaming halo from the PC, without using the PVR as a link to an xbox/ps3.