I'm running Windows 7 and a Sabrent external USB 2.0/Esata interface. The drive works fine via usb 2.0 but does not via esata. When I turn on the computer with the external plugged in and powered up, the computer locks up on startup. If I try hot swapping while windows is loaded, the drive does not show up.
How does your computer provide eSATA functions? Is it done with a special chip by Via, Silicon Image, nVidia, or some such company in addition to the "regular" SATA ports provided by the main southbridge chip? Most mobo's do it this way - using a special extra chip. If that is how your mobo works, check carefully in the documentation of drivers for the motherboard devices. These usually are on a CD of stuff that came with the mobo. The chip is considered a device on the mobo and Windows will need to have a device driver for it loaded in order to use it.