You may encounter the following error message when you try to start your Windows XP computer or you try to upgrade your current operating system to Windows XP:

STOP 0x000000ED (0xaaaaaaaa,0xbbbbbbbb,0xcccccccc,0xdddddddd) UNMOUNTABLE_BOOT_VOLUME

Note: The hexadecimal number, aaaaaaaa, bbbbbbbb, cccccccc, and dddddddd included in the message may differ according to the condition.
Cause of the Error

You may face this problem when one of the following is true:

  • The file system on your computer is damaged and cannot be mounted during the system startup.
  • Ultra Direct Memory Access (UDMA) hard disk controller is installed on the system and the following holds true:
    • BIOS configuration forces faster UDMA modes on the computer.
    • Instead of the 80-wire, 40-pin cable needed to connect the UDMA drive to the controller, you are using the standard 40-wire cable.

Note: If the error message is displayed when you start your PC for the first time when upgrading to Windows XP, then your current operating system will still work normally.

Some users may see the error message on the BIOS report screen that may state that incorrect cable is used on the system. You may not be able to see this error message on computers that have been configured for fast startup time.

Resolution Method

You can use the following methods to resolve the issue.

Note: The methods discussed here are for advanced users. If you are not comfortable using them, it is recommended that you contact external support for a resolution. You may also click the Send error Report to send the error to Microsoft support and seek their help.

Method 1: Repair the Damaged File System

If in the error message the second parameter 0xbbbbbbbb displays the value as 0xC0000032, it implies a damaged file system.

To repair the file system, perform the following steps:

  1. Boot your system with the Windows XP installation disk.
  2. on the Welcome to Setup screen, press R.
  3. Select the operating system installation you want to repair and then provide the administrator username and password.
  4. At command prompt type the chkdsk /r command and then press Enter. If this command fails to fix the file system, run the fixboot command.
  5. Type exit and press Enter to restart your PC.
  6. Your system should startup normally now.

Method 2: Fix the UDMA Controller Error

If your hard disk controller is UDMA, perform the following tasks to fix the error messages:

  • Start your computer and press Del or F10 to enter system setup-the key you press may differ depending on the BIOS installed on your system. When the BIOS settings are displayed, press the appropriate key to load the Fail-Safe default settings. Next, activate the frequently used options, such as the USB support.
  • If you have standard 40-wire cable installed on the system, replace it with 80-wire UDMA cable.