Just out of curiosity:
A friend had a WD external case + SATA 2.5 disk, which fell on the floor and broke. The disk ended in trash (uprepairable). Out of the broken case, i took the PCB, a model of control board named "4061-705030-101 Rev.AA" with 2(3) connectors -- the SATA current+data and the miniUSB plug on the other side. I plugged it with a disk on the one side, the cable on the other, and, yes, it worked!
So it worked for quite some time with SATA 2.5 HDDs and on 3 computers at least (2 laptops, one with win7 and one with winXP, and a desktop in office with winXP) and worked fine. But i needed it on another 2 winXP desktops, and it refuses to work. Windows pops the "found new hardware" asking for a driver... but this driver is never found anywhere, and nobody seems to know anything. The drive is only marked as an unknown "USB device" in Device Manager.
It is funny that on some computers with WinXP it works, on others not. I tried to see what those computers have in common, and as far as i can get (i am not going to search the whole globe for this!) is that they have an Intel CPU (in both properly drivers installed and working flawlessly).
So, any idea?
I had some time yesterday to experiment. I connected the same interface with a few SATA HDDs (2.5, 3.5) and i noticed that with some disks it works with others not, differently on different computers. So down at the disk level looking for differences, i checked the needed milliAmperes on the disks, and voila! (I think) it is a matter of power. It depends on the current given by the USBs. Strangely though, winXP thinks a driver is missing. :-)