Disk Management. If possible, view the thumb drive's disk structure within Disk Management to see how it's reported.
a. Disk(s)
o CD - represents system partition for U3 enabled thumb drive
o Disk - Fixed or Removable ? (Data partition for U3 enabled thumb drive)
b. Structure of Disk
o Partitions - Number and type (e.g. primary, extended, logical)
o File System(s) (e.g. Raw, FAT, FAT32, NTFS)
o Status - Healthy or ?
o Capacity - in MegaBytes (MB) or GigaBytes (GB)
o Free Space - in MB or GB
o Unallocated space on drive (how much, if any)
To access within Windows XP:
o select "Start" ->
o right-click "My Computer" ->
o select "Manage" ->
o within "Storage" category on left pane of "Computer Management" window, select "Disk Management".
Look for information in both the top right-hand pane and the bottom right-hand panes of Computer Management window.
2.
USBView. This is a utility provided within the Microsoft "Debugging Tools for Windows" package. It should indicate whether the device has connected and is recognized (I believe it at least reports the information from the device necessary to support "Plug and Play".) From the help file provided within this package:
USBView can enumerate USB host controllers, USB hubs, and attached USB devices. It can also query information about the devices from the registry and through USB requests to the devices.
Download and install the appropriate version of "Debugging Tools for Windows" (either 32-bit or 64-bit). You should find the "usbview.exe" file in its installation directory, e.g. "C:\Program Files\Debugging Tools for Windows (x86)". Double click on the executable to run it.
Here is a link to the 32-bit versions:
Install Debugging Tools for Windows 32-bit Version.