i have an external seagate hard drive that has USB and eSATA. i have used usb for about 2 years with it. I got an eSata cable to connect from the external drive to my sata PCI card. I am using windows 7 PRO. when using the esata the PC sees it but after a while it will disappear. i have to either reboot or goto - my computer - right click manage- computer management - then scan for hardware changes.