The system had one drive with two partitions both running Windows 7. The first one, I deleted. This didn't have the MBR or bootloader on it. The second one was kept, but resized to fit the whole drive. After I did this and restarted, there were duplicate entries in the bootloader. I ran both, and they gave me the same result: The drive letter is now J (I think) instead of F. The background is plain blue with no Aero theme, so it must be referencing the old drive letter. No taskbar, so I started Task Manager with Ctrl-Alt-Del, and ran cmd. If I type regedit, it says the system can not find the file specified, even if I do dir in :\Windows, I can see the file.

I booted from the recovery disk and messed with \HKLM\SYSTEM\MountedDevices, and now it won't boot at all, but it shows the error message and asks to go to Safe Mode, Last Known Good Configuration, and Start Normally. When I select Safe Mode/Start Windows Normally it says autochk not found - skipping autocheck, and reboots.

Last Known Good Config does not work.

I read that I should just delete MountedDevices and let it rebuild this. Should I do this and try to repair it after I do that? I'm scared I will mess things up permanently. I can't do a clean install, it's for someone else's computer, and there are settings in it that I can't transfer to another drive.

EDIT: After some research, I found this article:

In this image ( ) it shows 3 similar entries. This is because there are 3 partitions (System Reserved, Windows, and Manufacturer Recovery). Which one should I use? The middle one? Since the middle would be Windows? The ones that start with d5 49 3b ff are the ones I'm talking about.

EDIT 2: The first four bytes are the disk ID and the next eight are the partition offset. It would be the one with the middle value. I am going to try to see if I can follow the guide to recreate it.

  • Unless you tell us what you did exactly when you messed with the registry I am not sure if we can help with your problem. You likely caused more harm then good. – Ramhound Sep 11 '14 at 16:46
  • Deleted duplicate entries. There were the exact same D:, F:, and J: I removed D: and J:. I guess I should copy them back. – Phoenix Sep 11 '14 at 17:21
  • Here's what it know looks like. I don't know what these drives are. I can't even get a clear look at the Computer menu. – Phoenix Sep 11 '14 at 17:30
  • I edited two parts of the question. – Phoenix Sep 11 '14 at 18:00

If it is only a bootloader problem, windows repair disk should automatically be able to repair it (if you allow it of course). Boot from the repair cd and drop into the command prompt. There bootrec /ScanOS will scan all disks for any existing windows installations. If you find any you can add it to the bcd by bootrec /RebuildBCD. These operations should be non-destructive in terms of data. Though I strongly recommend a backup before you proceed. You can use any linux live CD with NTFS support and copy all data to an external drive.

Do not touch registry unless you fully understand what you are doing.

Boot from recovery/install DVD/USB and run "StartUp Repair" up to 3 times with rebooting after each run.

If this does not fix the problem open command prompt:

  1. Check if a partition on disk is marked active using diskpart.exe - usually the first partition is active. Eventually if no active partition present mark the first partition as active (it will hold boot related files)

  2. bootsect /nt60 all /mbr

  3. bcdboot Y:\windows (where Y: is drive letter for your Windows 7 partition)

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