You didn't mention the OS so I can't direct you to where it will be found but it should list the disk and give you an idea of its partition status. If it shows as un-partitioned space, something became corrupt and your options depend upon how important the data is that was written to the drive.
have a lacie 250 gb hard drive, USB 2.0
used two days ago, no problem, it is my back-up drive
yesterday, would not connect to computer; if i plug it in, computer makes ping noise suggesting that it sees it, but in the list of drives, under "computer" in windows explorer, the drive does not show up; it is listed as a connected drive, when i try to use the safe removal icon in the bottom right taskbar, but without an associated drive letter, ie other drive will say, "...storage drive (K):", this one will only have "...storage drive"; if i pull up device manager, and look under drives, it is also listed, says drivers are up to date, and device is working properly, but i cannot actually access it or see it in the "computer" to click on it
any ideas of what could be happening?

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