I am running Windows XP on a E6600 with an ASUS P5B Deluxe. I was never able to figure out how to make eSATA 'plug and play' on this platform. I wonder if it's an OS or hardware limitation. I am looking to build a new computer but I haven't figured out if I have to stick with an extra 1394b add-on card if eSATA is not 'plug and play'. Is eSATA 'plug and play' under windows 7? Also, can you fit a PCIe 1x into a 4x or 8x slot?