help, I cloned my 2Tb HDD to a 750Gb SDD now windows 10 doesn't boot

Matthew, welcome to these user forums.

Unfortunately yours is becoming a familiar cry for help where cloning is being performed without adequate preparation or planning, and where some basic rules are not followed.

At this point, I would recommend completely removing the SSD drive and ensuring that your HDD is replaced in exactly the same position (in terms of SATA connectors) as it was when working correctly.  Remove all other bootable media and check to see if Windows 10 will start to the point where you could attempt a 'Startup Repair'.

See KB document: 45831: Acronis Software: Unbootable System after Cloning Operation which offers some suggestions for how to try to recover your Windows 10 OS on the HDD.

See also: Windows won’t start – Guide for Windows XP, Vista, 7, 8, 10 - scroll down to the section: Fixes if Windows 10 won’t start and try the steps shown there.

Thanks Steve for the speedy response. Just for clarity when you recommend reinstating the HDD to the same position do you mean make sure it is napped to the c drive?

Also wondered if the resizing of the partition may have been an issue, could I resize it back again?

Regards,

Matthew

Matthew, I mean simply putting everything back to how it was when it was working correctly before attempting the clone.

A clone should not have involved resizing any partitions on the source HDD drive - this should be unchanged apart from the possibility of changes to the boot configuration data caused by starting a clone from within Windows.

The correct process for cloning should be as follows:

1. Make a full disk backup of your current working Windows OS HDD to an external backup drive
2. Identify how your Windows OS boots, see webpage: Check if your PC uses UEFI or BIOS - this is important for the next step.
3. Create the Acronis bootable Rescue Media - shutdown your system and boot this Rescue Media in the same way that Windows boots.
   Check that the Rescue Media will boot correctly and that you can access the Acronis application and see your HDD.
4. Shutdown, remove the current HDD drive and replace this with the SSD drive installed inside the system.
   Connect the HDD drive externally using a USB to SATA adapter.
5. Boot the system from the Acronis bootable Rescue Media (as in step 3.) and check that you can now see both the SSD (internal) and HDD (external) drives.
6. Perform the clone operation from the HDD (Source) to the SSD (Target) drive.
7. Shutdown, remove the external HDD drive and Rescue media.  
   Note: Do NOT attempt to boot into Windows with both drives connected - these now have identical drive signatures / contents and will cause problems with Windows if you do so!
   Note 2: Check your BIOS / EFI settings to ensure the SSD is shown as the correct boot device / priority.
8. Restart the system with just the cloned SSD drive and check that all is OK with Windows starting.  Put the HDD drive to one side until you are confident that all is OK and you no longer need the HDD.  Connect this via the USB to SATA adapter and format / repartition within Windows when you want to re-use the HDD for another purpose. 

Hi Steve,

Acronis may not have changed the partition size but it seems to have made the disk invisible - I can see a windows folder on the f drive and windows can recognise a windows 10 pro installation - but can't repair it.

Like you I'd expecte dthe original HDD to have been untouched, but then guess it may have altered the partition to matcvh the 750Gb SSD drive I wanted to clone onto.

Will keep trying,

Thanks,

Matthew

Matthew, I would not expect Acronis to touch or alter any of the source drive partitions when doing a clone - any adjustment of partition sizes will always be applied to the target drive for the clone operation, i.e. reducing partition sizes on the 750GB SSD.

If you can see that the original HDD is not visible, how are you able to look at this?  Are you booting from removable media?

Hi Steve

From the command prompt I'm running in dos and can see the folders are still there.

As the original HDD is much larger than the SDD I was concerned that the HDD partitions would need to be reduced to fit.

Matthew, when you say you are running in DOS, do you mean that you have booted from DOS media or that you are using the Windows Command prompt that you can access from the installed OS or from recovery media?

If it is the latter then have you tried to commands shown at: https://neosmart.net/wiki/windows-wont-start/#Fixes_if_Windows_10won8217t_start

Something else you can try is to use the Diskpart command to check what partitions are on your drive - see DiskPart Command-Line Options - see example below which shows that my partition 3 is the Active partition used by Windows to boot my laptop.

Microsoft DiskPart version 10.0.14393.0

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

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          931 GB  7168 KB

DISKPART> select disk 0

Disk 0 is now the selected disk.

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    OEM                141 MB    31 KB
  Partition 2    Primary             10 GB   141 MB
  Partition 3    Primary             51 GB    10 GB
  Partition 0    Extended           828 GB    62 GB
  Partition 4    Logical             83 GB    62 GB
  Partition 5    Logical            147 GB   145 GB
  Partition 6    Logical             52 GB   292 GB
  Partition 7    Logical             30 GB   344 GB
  Partition 8    Logical             10 GB   374 GB
  Partition 9    Logical            505 GB   384 GB

DISKPART> select partition 3

Partition 3 is now the selected partition.

DISKPART> detail partition

Partition 3
Type  : 07
Hidden: No
Active: Yes
Offset in Bytes: 10890270720

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
* Volume 1     D   WindowsVist  NTFS   Partition     51 GB  Healthy    System

DISKPART> select partition 4

Partition 4 is now the selected partition.

DISKPART> detail partition

Partition 4
Type  : 07
Hidden: No
Active: No
Offset in Bytes: 66633025536

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
* Volume 2     C   Windows10    NTFS   Partition     83 GB  Healthy    Boot

DISKPART>