Windows 10 Boot Black Screen Blinking Underscore

Hi,

Thank you for posting in Microsoft Community.

I understand that you are facing issues regarding your computer display. Let me help you resolve the issue.

1. What is the make and model of your computer?
2. Can you see any error message/ error code on the screen?
3. How did you upgrade Windows 10? Was it Windows update or Media Creation Tool?

The main causes observed so far are driver issues, output to unexpected port, and possibly also issues with the Lock Screen app. Please use these steps:

Method 1:

Try connecting to different video outputs on the PC. Sometimes a change in driver can cause the video to be sent:

1. To a different Adapter: from integrated graphics to a discrete card or vice versa.
2. To a different output: from HDMI to DVI, Display Port to VGA, or any other combination.

Method 2:

Try to boot into Safe Mode with Networking or Enable low-resolution video.

1. Press and hold the shift key while clicking on Restart at the login Screen (Bottom right corner).
2. Select Troubleshoot and click on Advanced Options.
3. Select Startup Settings and click on Restart.
4. After restarting, choose Enable Safe mode with networking or Low Resolution Video.

Also check Device Manager and look for Display Adapters.

If you see 2 items under Display Adapters, disable to integrated video card (e.g. Intel HD 4000 or AMD Radeon HD 4200) and restart. (Try vice versa if it does not work).

If you see 1 item under Display Adapters, rollback the driver or uninstall the display adapter in Device Manager, and enable the option to delete driver software.

If the issue still persists, I suggest you to download and install the latest drivers from your computer manufacturer website and check if it helps you. Or try rolling back to the previous version of the driver, which you have recently updated. Check if it helps

I hope the information helps. If not, please reply back with the updated status and details. We will be happy to assist you accordingly.

Thank you

1.) Athlon II x4 cpu

Gt 240 graphics card

2.) No.

3.) Media creation tool.

I tried method 1, to no avail.

I cannot try method 2 because it gets stuck on a black screen with an underscore. There is nothing i can do computer wise, other than go into the bios. 

That is what the screen looks like.

Update: My dad came over and lent me his laptop. I will make a usb boot disk to try and fix this problem.

Update 2: Led to same screen. Also tried an amd graphics card. Only thing I have left to test is an HDMI output, however I will have to bring my tv over.

YES, I HAVE THIS KIND OF PROBLEM TOO, AT FIRST WHEN I TURNED THE COMPUTER ON IT SHOWED THE ASUS LOGO AND THEN, IT JUST WENT TO BLACK SCREEN WITH A BLINKING UNDERSCORE. CAN YOU HELP ME? I HAVE VERY IMPORTANT FILES IN HERE. I UPDATED WINDOWS 10 WITH MEDIA CREATION TOOL. :(