Upgrade from build 10061 to 10074 fails (Inaccessible Boot Device)

So..:

I learned a very useful bit of info. Actually, quite a few things. For starters, at any point (after a few seconds anyways) during Windows Setup after it reboots, Shift+F10 brings up a cmd window. This window uses the System account (to check, enter the set command and look at the value for %USERNAME%). Let the games begin.

Found from DiskPart, as I suspected:

Code:

Microsoft Windows [Version 10.0.10074]



H:\$WINDOWS.~BT\Sources>diskpart


Microsoft DiskPart version 10.0.10074


Copyright (C) 1999-2013 Microsoft Corporation.
On computer: MININT-KVSOTNG


DISKPART> list volume


  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E   J_CCSA_X64F  UDF    DVD-ROM     3606 MB  Healthy
  Volume 1     C   Win 7        NTFS   Partition    300 GB  Healthy
  Volume 2     F   XP BE        NTFS   Partition     15 GB  Healthy
  Volume 3     G   Data         NTFS   Partition    460 GB  Healthy
  Volume 4     H   Win 10       NTFS   Partition     48 GB  Healthy
  Volume 5     D   System       NTFS   Partition   1500 MB  Healthy    Hidden


DISKPART>

Now, let me back up a bit:

I had already moved the actual files back into an actual DriverStore\FileRepository folder. I used the system account, you can see how to do that here, but the TL;DR is use Sysinternals' psexec from an elevated cmd prompt like so:

Code:

psexec -i -s -d cmd

Follow that (in the new CMD window) with

Code:

whoami /user

to double-check that it worked (side note: on an old Windows version {like XP}, enter the set command and look at %USERPROFILE%). Also note that you can launch things (like Explorer, regedit, etc etc) from this System cmd prompt and the new processes will be run as System as well.

So, I don't know if what I did during setup would have worked, as I had already taken care of the problem by moving the files.

To make this work, I noted that by having compression on, the 16GB folder became 9.7GB on disk. I then disabled hibernation with

Code:

powercfg hibernate off

, saving myself 5GB (your amount will vary depending on the amount of physical memory you have).

I then used WICleanup (working download link is now here) to delete my orphaned/unused MS Installer (*.msi) and Installer Patch files (*.msp) from \Windows\Installer (AFTER backing the entire folder up -- you don't want to be caught looking for a specific version of an .msi file from one of your programs while trying to upgrade / uninstall it; I've been there, it's a pain. I know these are supposed to be unused... but you don't know for sure they won't be needed later (as I can attest from previous experience!). Back 'em up! In WICleanup, you can select the first in the list (not the checkbox, I mean highlight the row), then scroll to the bottom, hold the shift key, and click to select the last row. Then, click the checkbox of any of the now-selected rows, and all of the items will be checked. To delete, for every entry, you're going to have to press "Y" to confirm deletion and then Enter or Spacebar to acknowledge success, I would do it in alternating fashion (Y-Space-Y-Space-Y-Space....) unless you want to click two boxes for every item being deleted...
So that (WICleanup) saved me 1.5GB.

I ran CCleaner, ran Disk Cleanup on the system files and also under additional options erased all but the most recent restore point.

Also, I knew Win 10 setup wouldn't take as much space during installation, as all temporary files, backup files, new files, etc etc are all going to be compressed since the drive is compressed by default now.

So, with the drivers on the Win 10 drive again, I had 14 or 15 GB of space free IIRC. Initiated 10074 setup from DVD I burned. Now we're at Windows setup and I investigate (using Shift-F10 cmd prompt) the drive letters, yup, Setup assigned my hidden system partition to the letter D.
I then opened regedit, (this is the registry of whatever Windows environment is responsible for the setup) and went to HKLM\SYSTEM\MountedDevices
Copied the value for my Data partition under \DosDevices\G: (be sure to get it all , it will also select to the right / left) and then went to \DosDevices\D: and replaced the values there with the values for my data partition. Then I deleted the \DosDevices\G: entry (this makes Windows re-assign that drive).
Upon the 2nd phase of Windows Setup, loaded up DiskPart and my Data partition was listed as drive D.

So there's that.

For more reading, (definitely if you are at all confused or unsure of what I did) check these out:

Editing the MountedDevices Registry Key
How to Use the Diskpart Utility to Assign and Remove Drive Letters (couldn't really do this while the D: drive was in use (although it might not have been once Win Setup loaded, but I didn't want to chance it), but I knew if I edited the registry, it would take effect on next boot, so I did that instead)

Oh, and here's where the Windows Setup logs (failed or successful) get put: Log files that are created when you upgrade to Windows Vista from an earlier version of Windows

I just upgraded to 100122 after deleting the filerepository contents, everything seems ok. Running disk cleanup (system) and it found 10gb of drivers packages and 15gb previous installations.

So far so good, only took about 30 mins to upgrade, seems much more polished.

Edit: FileRepository is no 1.02gb

Update -- I just went through with WinDirStat and found which folders took the most space, found which ones looked similar in structure, selected them all, and hovered over them while selecting and based my criteria on what the first file in the folder was -- I only allowed one folder to exist that started with the same file. By doing this, I slimmed down my drivers to 1 or 2 GB total, which allowed me to update.

Now that Disk Cleanup has the delete old / redundant drivers, I should have no more problems.