I was considering buying Sony Vegas 9 Pro, and I built a PC with an AMD Phenom II X4 965 BE 3.4GHz Quad-Core processor, 4GB DDR3 RAM, Radeon HD 5770 GPU, 1.5TB HDD with Windows 7 64-bit. I was wondering what I can do to make my computer edit HD videos smoothly. I never edited HD video before, so I don't know if my PC can manage. Thanks!