And if the above doesn't help, post a Sandra Lite report on the PC. Having a "highly-spec'd" computer is worthless if there is some hardware incompatibility. And sometimes a piece of hardware can work under one circumstance and not work under another. An example of this is my own rig, which runs HD/Native (PCIe card) with a 192 flawlessly day after day, but it will not run with my new MBOX Studio at all
