Mike Squires wrote:If it's a desktop, simply purchase an internal PCI-E USB 3.0 card that is compatible. Many of us have done it, and it works fine. They only cost ~$25.
No, it won't work because you can't fit a PCIe Extension card into the X51 (there is only one PCIe Slot that's used by the graphics card). But in any other case this should work.
Other than that I can only say that your Alienware is not listed as compatible. The USB 3.0 Chipset should be but there seem to be some problems that make it incompatible. However, there are Alienware Desktops that have no problems with the Shuttle (I've used mine without problems on my friends computer).