You can fix Stop 0x000000ED (UNMOUNTABLE_BOOT_VOLUME) Blue Screen Error by running the CHKDSK command in the Recovery Console. This particular Blue Screen of Death (BSOD) means there is a critical error in the NTOSKRNL that is preventing Windows from booting normally.
The following procedure should help you correct the issue assuming you have not made any recent changes in the BIOS or have attempted to configure RAID. If you have done either of those, set the BIOS back to default and revert the RAID settings back to Autodetect.
Fix Stop 0x000000ED (UNMOUNTABLE_BOOT_VOLUME)
You will need a Windows disk, as you have to run a command from the Recovery Console. You will boot to the Windows Disk and follow the prompts until you get to the part where it asks if you want to run the Recovery Console. Press R on your keyboard to launch it.
If you’re asked which installation you’d like to log into press 1.
Type in the Administrator’s password when prompted to and hit enter. If you have no admin password setup just press enter.
At the command prompt type chkdsk /r and press enter. The disk checking process will begin and Windows will repair any errors it finds. This entire process can take a long time to complete. When done type exit and hit enter to restart the computer.
If this corrects the problem, be sure to take the opportunity to backup any important data and then run Windows Update. Anytime you have a critical hard drive error, you want to make sure the drive is reliable to use going forward. There are free programs out there to run diagnostics on your hard drive. A good place to begin is with the manufacturer of your drive (Western Digital, Maxtor, Seagate, etc). They will have tools on their site to test the drive. Do not run those tools or do anything hard drive intensive until you have backed up your data.