Many thanks, Colin. I had not found the Disk Management function previously.

Unfortunately, the problem persists. The disk appears in Disk Management,
its status is Online. However, when I right click the volume, the option to
Change Drive Letter and Paths is grayed out. The only options are Delete
Volume and Help (which doesn't have an answer for this issue).

Here's a piece of information that could be the root of the issue: the data
on the disk was written from a Mac. But it was written to be readable by
both Macs and PCs.

Any thoughts? Again, many thanks.

"Colin Barnhorst" wrote:

> Is it assigned a drive letter in Drive Management?
>
> Right click Computer, choose Manage, expand Storage, and choose Disk
> Management.
>
> "tgeorge" <tgeorge@discussions.microsoft.com> wrote in message
> news:A5B9369B-14C0-486A-9EAB-86401B9D9D4E@microsoft.com...
> >I am connecting an external hard drive (Acomdata 250G drive - pretty
> > standard) via USB to my HP laptop running Vista. I am able to see the
> > device
> > listed under Disk Drives in the Device Manager. Drilling into Properties,
> > I
> > see that the device is running properly and, having re-loaded the device
> > drivers, I have the most recent drivers.
> >
> > The issue: I am unable to see the device listed in Window Explorer, and
> > thus
> > I can't drill into the folders to get at the content.
> >
> > Any help is greatly appreciated.
>