Your system may not assign a drive letter to a Microdrive due to inadequate system resources. Follow the instructions below to check your system resources.

Check Your System Resources

1. Select Start > Settings > Control Panel, then click on the System icon and select the Device Manager tab.
    
2. If it is not already expanded, click on the '+' before the Hard disk controllers icon to expand the heading.
    
3. If there are any conflicts, you should see an exclamation mark in a yellow circle on the icon.
    
4. If the driver diskette was used during the initial installation of the Microdrive, you should see the Microdrive listed under hard disk controllers.
   
   If you did not use the driver diskette, the Microdrive may show up as a Standard IDE/ESDI Hard Disk Controller. In this case, you may need to run the md9xfix.exe utility.
    
5. Click on Microdrive under Hard disk controllers and select the Resources tab. The Microdrive should be assigned an Input/Output Range and an Interrupt Request (IRQ). If not, you will have to free up an IRQ resource.
   
   To free up an IRQ, disable any device or devices not needed that have an IRQ allocated to it. To do this, double-click the device and selecting the "Disable in this hardware profile" check box.
   
   Some suggested devices to disable are the Infrared device, under “Sound, video and game controllers,” “MIDI or MPU-401 Compatible device” or the “Game, Gameport or Joystick” device. Reboot the system after disabling these unused devices.
    
6. If you have an IBM ThinkPad 600 series laptop, you may also have to disable the warm swap option of the device bay. See Using Microdrive or Travelstar E with ThinkPad 600x.

Viewing IRQs

To view what IRQs are being used by which device, go to the Device Manager tab in the System Properties and double-click on "Computer". Select the View Resources tab and select Interrupt request (IRQ). There are 16 IRQs, 0 through 15. Any IRQ not listed may be available for use by a device.