"It seems like a complicated issue. The solution to the MBR being in the wrong location would be to boot into the Recovery Console, and run fixmbr.
If that command is incorrect (it was the WinXP method), I've read the following command may also work:
Bootrec.exe /FixMbr
However, the issue here is that, as far as I'm aware with Windows 7, you still need the disc to get into the recovery console. If your Throttle is plugged in during the MBR fix, it may want to write it to the same location. The solution would be to boot from a DVD, which then voids the entire point of installing from the drive in the first place.
I would expect that Windows would write the MBR to the first SATA drive logically ordered in the BIOS. Some motherboards may list the eSATA ports first, while others may list the hard drives first. So, at least according to my theory, the eSATA installation may work on some machines based on the motherboard, and not others."
