my hp tower will not assign a drive letter to my new toshiba 3tb external hard drive. i have a 2tb toshiba external hard drive that works fine with the hp tower. the computer recognizes the device and installs the hardware. I have gone to device manager and the drive is recognized there. I have uninstalled the drive from device manager and it does find it again and install the hardware. Still it doesn't assign a drive letter. I have tried different cables. The lite on the drive shows up also. I have tried assigning a letter to the drive from device manager but that option isn't available. I can only format the drive. I cannot figure out why this toshiba 3tb drive isnt working when the toshiba 2tb drive is. I need help and formatting isn't a option as the drive has files on it I don't want to lose. The hp tower has windows xp service pack 3. my other computer (Lenovo) is running windows 10. the Lenovo has no issues with the 3tb drive.