I don't recommend running WoW and Windows on the same drive. You can increase your speeds a few ways. 2 small 7200 RPM drives that you setup in a RAID0 array (this is how I ran for a long time and is the cheaper route) or with a Solid State Drive. These are popular because they have no moving parts and are wicked fast :/ Even a second drive with just WoW on it will help some. I only make this recommendation because you said you may want to stream.