Try USBDLM V4.2.4 – USB Drive Letter Manager for Windows 2000, XP, Server 2003 and Vista.
Have you tried this process? (More info can be found here)
To work around this issue if the new volume appears in Disk Management, specify a different drive letter for the new device or volume. To do this, follow these steps:
- Right-click My Computer, and then click Manage.
- Under Computer Management (Local), click Disk Management.
- In the list of drives in the right pane, right-click the new drive and then click Change Drive Letter and Path(s).
- Click Change, and in the drop-down box, select a drive letter for the new drive that is not assigned to a mapped network drive.
- Click OK, and then click OK again.
There might be a default settings of your computer system or Operating Systems which always assign a certain drive letter for any external storage devices detected in your computer. You have to carefully check that configuration and try to change the drive letter.