How good is this computer build, What could i improve?

I generally don't answer these questions because it turns into a debate since everyone has their own preferences. However from the looks of things you have a pretty sweet box there. I might suggest going for a 1 Kilowatt PSU since all of your hardware(CPU, Video Card, Mobo, CPU cooler and Case fans) is going to take some power and going over the necessary requirement will make the PSU work less and give you cleaner power; as well as leave room for expansion in case you add some bigger hardware. Also I would go with Windows 7 Professional it has the most features for the price (Windows 7 Ultimate only has two more features: Multi-language support and BitLocker). The setup looks like it should last you for years to come. Four GB of RAM is more than enough for running games and Audio/Video/Photo editing software. Even if you get into running Virtual Machines. Also the Intel i7 is a powerhouse and even being an AMD fanboy has me watering at the mouth. I can't tell you about video cards as I don't know all the ins and outs of them, but it looks like a good one. Have fun with the build.