Drive not detected, except in Device Mgr

I have an external 120GB drive in a caddy. Had it connected to a laptop
running Partition Magic & was experimenting with resizing clusters when the
program & drive stopped responding, had to End Task. Contents of the drive
not vital & backed up anyway.

Drive now will not be auto detected with a drive letter/autorun search and
the pop-up window at all on the laptop via USB or firewire (or show up in My
Computer), tried several cables & different USB ports, rebooting etc.

However it IS detected & runs perfectly when connected to my desktop PC -
the contents are accessible and PMagic reports the cluster size is
unchanged.

On the laptop the drive is detected in Device Manager under Disk Drives as
ST312002 6A USB Device. Uninstalling & reconnecting tells me the device is
installed and ready for use, but still invisible to My Computer.

I could accept if I'd stuffed up the drive somehow, but it's frustrating to
have it working fine on another computer!

 

Karl Engel wrote:

.....

You just have to assign a drive letter from the disk management tool
(management - drive management, right-click and choose a proper drive
letter).

 

Yay! Thanks muchly. In years of messing I'd never come across this
management tool.

Two questions - how do you get to the Computer Management (Local) area
normally (I used a link from a Help & Support query)?

This 120GB NTFS drive shows up as 111.78GB Healthy & 12.92GB free space. Now
I know with formatting and the fact that a GB is really 1024 MB it will
never read 120 Healthy, but it should be a bit higher than 111 shouldn't it?
The clusters are 4KB.

Partition Magic says I can resize the main partition from 114,463.1MB to a
maximum of 127,680.7MB but when I try and click Finish it says 0 Operations
Pending and Apply is greyed out.

I suspect this is a dumb question showing I haven't grasped the maths rather
than a problem, but shouldn't P Magic know the partition can't be that big
if it won't do it?

 

Quickest way is to right click on "My Computer" Icon on Desktop and select
Manage from the context menu, then Disk Management.

My 320GB drives format to 298GB storage space, so yes there is some
overhead.