Windows 10 won't boot after update

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Recent installation of updates might have caused conflict which might have corrupted the
system files. I understand that you are unable to boot to Windows 10 Technical Preview after installing the Windows updates.

To further investigate with the issue, please let us know. 

1. What is the make and model of your computer?

2. Do you have Windows 10 Technical Preview ISO media?

If no, create one by following the link below

http://windows.microsoft.com/en-us/windows/preview-download?ocid=tp_site_downloadpage

Follow these methods and check if it helps:

Method 1: Automatic Repair attempts to automatically diagnose and fix common issues that may cause Windows to not start properly.  It will scan various settings, configuration options, and system files for corrupt files and settings.  If it detects anything, it will automatically attempt to fix them for you.

a. Contact the computer manufacturer to know on how to change the boot order of the computer. You will have to change the boot device to CD/DVD drive and then boot from the Windows 10 installation disk.

b. In the "Windows Setup" dialog box that appears, set the Time and currency format, Keyboard or input method and the language to install and then click "Next".

c. Click on "Repair your computer" from the lower left corner.

d. From the "Choose an option screen", click on "Troubleshoot".

e. Click "Advanced Options" in the "Troubleshoot" screen.

f. In the "Advanced Options" screen, click "Automatic Repair".

g. Follow the on-screen instructions to complete the Automatic Repair.

Now, try booting the computer. If the Automatic Repair does not help, then try performing a System Restore from the "Advanced Options" and check if that helps.

Method 2: System Restore allows you to restore your computer to a previous state quickly and easily without losing any of your files or personal settings. Sometimes when you install programs or drivers, they may affect some of the system settings and prevent other programs from working correctly. You can use System Restore to revert these settings back to their previous state.

Try to boot to Windows using the disc to perform a System restore.

a. Insert the installation DVD or USB and boot Windows 10 Technical Preview from it.

b. In the ‘Windows setup’ page select the ‘language to install’, ‘Time and currency format’ and the ‘keyboard or input method’ and click on ‘next’.

c. Click on ‘Repair your computer’ and select ‘Troubleshoot’.

d. Click on ‘Advanced options’ and select ‘System Restore’ and select the operating system to perform the restore.

Disclaimer: Application /programs that were installed after the last restore point will be lost. You may have to reinstall the application/programs. Once you are able to boot to normal mode, you may also check in Windows update history for any failed updates and the error codes.

Keep us updated about the status of the issue.