I haven’t posted in a while, and I encountered an UNMOUNTABLE_BOOT_VOLUME error on a clients machine earlier this week. This error is displayed while booting Windows XP and appears in the form of BSOD (Blue Screen of Death). The reason for this problem/error, the boot.ini file is corrupt.

I would recommend that only someone with knowledge of installing windows and changing BIOS settings performs this fix. This is ment to be a guide, and I take zero responsibility for any errors that may arise.

To fix this problem, you need to boot to a bootable Windows XP installation or boot disk and do a repair on windows. This can be accomplished by placing the boot disk in the CDROM drive and rebooting the computer. Before the computer passes the setup screen, you need to enter the BIOS (generally by hitting f1 or f2 for setup) and change the disk boot order to boot to the CDROM drive first, Save Settings, exit the BIOS, and if needed reboot the computer by hitting ctrl-alt-delete. Doing this will force the machine boot to the CDROM drive (if you encounter the blue screen error again, the machine booted to the hard drive instead of the CDROM drive, check your bios boot settings and try again).

Once you have booted into the windows boot disk, you need to make the ‘R’ selection for Recovery. This selection will be on the first screen after the CDROM boot process has completed.

Once the selection has been made for the recovery console, it will look like a DOS-Type prompt. Type these commands:
chkdsk /p
the check disk process will run, once this process has completed, type this command:
fixboot
Select yes, by hitting Y

Once the boot has completed it should boot into windows. IMPORTANT: remember to change your BIOS boot settings back to normal. The boot settings should resemble something like this:

a: – floppy drive (if you have a floppy)
c: – hard disk drive
d: – cdrom drive

Once the BIOS settings have been properly set back to normal, save, exit and reboot. The computer should now boot back into Windows XP.

If you would like to learn more about fixing your own computer, check out this ebook.