Windows XP - "STOP 0x000000ED UNMOUNTABLE_BOOT_VOLUME" error message
If you get this error after a restart or upgrade, then do the following from recovery console after booting off the XP CD again:
You access the recovery console from your Windows XP CD by booting of it. Unfortunately some manufacturers CD's do not have this option, but if you download the Windows XP boot disks you will be able to use the Console.
Once you log into the recovery console type the following command: