I have an old PC for older titles but alas it is only 40GB, so I bought a 320GB one today. I'm not fussed about losing a few games but how do I transfer the current OS (Win XP) and move it over to the new drive? I've only added HDD's into PC never replaced one. I have a few USB drives if that will help, or will I need to use my current PC's HDD cables for transfer etc? It's a prebuilt if that affects anything, properiety stuff etc.