black screen with blinking line in upper left corner

I am running windows 10, from windows 8. Free download.
I was usinf Skype, and the sound went off. I tried to restart my desktop, and after upgrade and restart, screen just black with blinking line.
What to do to repair windows 10?
Please advice.
Best regards, John From Denmark

Hi, suggests it's not seeing your disk at all - nothing to boot from.

Check your connections, check your disk - e.g. using a live boot disk or connect it to another PC.

If you can manage to read it again, run chkdsk on it.

Actually looks more like BOOT sector error, if disk wasn't working at all it would ask for "Bootable disk" or something like that depending on BIOS.
Check BIOS to see if disk(s) are detected.

Hi, suggests it's not seeing your disk at all - nothing to boot from.

Check your connections, check your disk - e.g. using a live boot disk or connect it to another PC.

If you can manage to read it again, run chkdsk on it.

sorry, I need help HOW to do, not WHAT to do.
live bood disk?? makes no sence to me
Best regards, John

Actually looks more like BOOT sector error, if disk wasn't working at all it would ask for "Bootable disk" or something like that depending on BIOS.
Check BIOS to see if disk(s) are detected.

How to do?
Check BIOS to see if disk?? are detected. Makes no sence to me.
Best regards, John

Hi, suggests it's not seeing your disk at all - nothing to boot from.

Check your connections, check your disk - e.g. using a live boot disk or connect it to another PC.

If you can manage to read it again, run chkdsk on it.

Sorry. it does not do any help to me at all.

I do not ask WHAT to do, but HOW to do.
Best regards, John

Try this:
1. Make sure you have Window 10 install disk or bootable medium e.g. flash drive that matches your current Windows build.
I'll assume it's a DVD.
2. Open your disk drive if it's a DVD
3. Insert DVD
4. Close disk drive
5. Make sure you know how to get your PC to boot from said DVD
6. Do a startup repair
Startup Repair - Run in Windows 10 - Windows 10 blog

If you're very lucky, your problem will be fixed. If not please post back.

But it should tell you if it sees your HDD or not.

If any of the terms I used are unfamiliar to you, Google or other search engine will help.

CAPITALS ARE UNFRIENDLY.

Actually looks more like BOOT sector error, if disk wasn't working at all it would ask for "Bootable disk" or something like that depending on BIOS.
Check BIOS to see if disk(s) are detected.

Hi- depends on the BIOS as you say. My laptop experience is of the _ top left.. no message if no disk.

Try this:
1. Make sure you have Window 10 install disk or bootable medium e.g. flash drive that matches your current Windows build.
I'll assume it's a DVD.
2. Open your disk drive if it's a DVD
3. Insert DVD
4. Close disk drive
5. Make sure you know how to get your PC to boot from said DVD
6. Do a startup repair
Startup Repair - Run in Windows 10 - Windows 10 blog

If you're very lucky, your problem will be fixed. If not please post back.

But it should tell you if it sees your HDD or not.

If any of the terms I used are unfamiliar to you, Google or other search engine will help.

CAPITALS ARE UNFRIENDLY.

Sorry.
I do not have any windows 10 disk. I got windows 10 as a free download/upgrade.
My pc does start up, meaning: black screen with some start up informations as it always has done. After a short period, I have black screen with blinking line (Cursor?) at upper left corner.
Thanks for your assistance.
Best regards, John

These are freely downloadable, and useful to keep if you need either to do an in-place upgrade repair (see Tutorial section, just search for 'in-' or reinstall.

Windows 10 ISO Download - Windows 10 blog