Boot Into Safe Mode
If you’re getting the Blue Screen of Death at startup, it could be a result of a bad application, driver issue, or other hardware quirk causing problems on boot. If you can, Google the stop code that appears and see if it gives you any insight into what’s wrong.
Chances are, though, you’ll have to boot into Safe Mode to fix the problem. This used to be an easy process in Windows 7, because all you had to do was press F8 as you booted up. It has become much trickier in later editions of Windows, but usually if you interrupt the boot process three times—say, by pressing the reset button as Windows tries to boot—it’ll take you to the Automatic Repair screen, where you can click Advanced Options.
Alternatively, you can create a Windows installation drive using a friend’s PC and boot from that directly, choosing your language and selecting Repair Your Computer when given the option. Either of these methods should eventually get you to the Choose an Option screen, where you can click Troubleshoot > Advanced Options > Startup Settings and reboot the computer. (If you don’t see the Startup Settings option, you may need to click “See More Recovery Options” along the bottom.)
Your computer should then give you the option to boot into Safe Mode, Safe Mode with Networking, or Safe Mode with Command Prompt. You can try any of these, though the most minimal Safe Mode is probably your best bet, unless you need to access the internet (in which case, choose Safe Mode with Networking). This will load Windows with only the most crucial drivers and services running.
If you installed any new hardware recently, try uninstalling its drivers from Safe Mode. If you think a new application might be to blame, get rid of that too. BlueScreenView can help you look back through your most recent Blue Screens of Death to see the file that caused the problem, or any bug check strings and codes to Google.
You might even try running System Restore to try and get your PC back to the last known working configuration. Reboot the PC normally to see if it fixed the problem. If not, you can enter Safe Mode again, or try moving on to one of the next troubleshooting steps in this guide.