If you get the blue screen of death at startup, it may be the result of a poor application, driver problem, or other hardware that causes startup problems. If you can, Google can stop the code displayed and see if it gives you insight into what's wrong.
However, it is important that you start in Safe Mode to correct the problem. This was a simple process in Windows 7, because all you needed was to press F8 when you started your computer. It has become much more difficult in later editions of Windows, but usually if you cancel the startup process three times, such as by pressing the reset button that Windows tries to start – go to the Auto Repair screen, where you can click Advanced options.
Alternatively, you can create a Windows installation device using a friend's computer and start directly from it, select the language and choose "Repair your computer" when you get the option. Either of these methods should eventually get you to "Choose an alternative" screen, where you can click Troubleshoot> Advanced Options> Initial Settings and restart your computer. (If you do not see the Start Settings option, you may have to click "See More Restore Options" at the bottom.)
Next, the computer should allow you to launch in Safe Mode, Safe Mode with Network, or Safe Mode with Command Prompt. You can try one of these, but the least secure mode is probably your best bet, unless you need to access the internet. This will load Windows with only the most crucial drivers and services running.
If you recently installed any new hardware, try uninstalling the drivers. If you think a new application can be blaming, get rid of it too. You can even try to run System Restore to try to get your computer back to the last known work configuration. Restart the computer normally to see if it resolves the problem. If not, you can re-enter Safe Mode, or try one of the following troubleshooting steps in this guide.