USB Hitachi external hard drive had no problem running under Windows XP as a secondary drive. Put same drive on Windows 7 computer, not working. The drive assignment E: shown under My Computer and its property shows as an empty drive.
Windows 7 can't read 400G saved data and the error message is "CRC" error and asking format the drive which I say no. Attach IDE HD drive shows no problem accessing under Windows 7. Look like Windows 7 has the problem of accessing usb type of external hard drive.
That's a bit weird.
It implies the drive talked to the USB chip
inside the enclosure, and the drive reported a CRC error
off the platter. It's not likely to be a USB host to
USB peripheral error (bus interface issue).
When you say "WinXP Computer" and "Windows 7 Computer",
I have to assume these are physically different computers.
USB hard drives can have power problems. A 2.5" drive
in a USB enclosure, is allowed to draw 500mA from the
USB bus. Sometimes they draw too much current. But
your CRC error is not a typical error from such an event.
Usually, the drive won't spin up properly, if there is a
power problem. If there is a power problem, you might not
get any reaction from the drive at all (not detected).
If you're using a 3.5" drive, with an external power
adapter, then it's less likely to be a USB bus
power issue. The adapter powering the drive can
still be defective. But again, it is pretty difficult
to get to the level of being able to read the disk,
and a power problem causes a CRC error. The hardware
should screw up well before you get to that point.
You would need a multimeter, and access to the
inside of the enclosure, to verify the voltages
are OK. If a 12V adapter gives less than around 11V,
the drive will not spin up.
Now, maybe the Windows 7 computer is attempting to
read a different sector than the WinXP one. But
I don't have a theory for why that would be, so
it's pretty difficult to propose that as a part
of the root cause of the problem.
Paul
