New Ultra 4 RNDU400 and 3TB Drives

What application within Windows 7 did you use to see if it recognized the drives? If you used Computer or Windows Explorer, they will only recognize FAT or NTSF formatted drives. They will not 'see' a non formatted drive or a Linux formatted drive. The drives should be visible in the boot sequence listing of devices (typically covered up by the splash screen). The best way to have a Windows 7 PC to see the drive is to open Disk Management. Start -> Control Panel -> System and Security, then click on Create and format hard disk partitions. (Note: despite the heading, you will just be looking for information rather than actually formatting the drive). It will show the partitions, but will not recognize the formatting or data.

ESATA is not quite the same as SATA, but the difference is the connector and the cable. The actual eSATA connector has the key horizontal on one end of the plug, while SATA has it turned downward to form an elongated L laying on it's side. Electrically, they are the same, connecting directly to the PC's SATA controller. Most of the eSATA connectors on laptops are eSATA/USB connectors.