Please can people help me with this as im going to be buying the i5 i have a Pentium 2.50GHz and the gtx 770 if i upgrade to 4670k would it be able to run thanks
There's no doubt you should upgrade to the i5, as your Pentium will bottleneck hard. But as for the PSU, 450W would likely not be enough. I would look towards a XFX 550W (still would be pushing it a little), or a Seasonic 620W unit.
Just saying, that with that i5 your computers going to be awesome. I'm currently running an i5 4760k with a evga gtx 770 and I have to say its a beast performance wise. Your power supply that you currently have isn't going to cut it though, I bought a 700w thermaltake psu. It's on sale on newegg for $60 right now and you can save another $20 if you use the mail in rebate. It would be perfect for your system and could handle overclocking also.