Unable to reset PC

Hello.

It's been less than a month since you migrated to W10?
That's the deadline to be able to downgrade.
You can try this, but I don't believe it will work:
Unplug the PC.
Remove the battery (if it's a laptop).
Press and hold the power button for a minute.
Plug it back in.
Start it up.

Did you back up your personal data?
Do you have a partition with the system and personal data,
or a second partition dedicated to personal data?

You can also reinstall W10 with the DVD if you want to; why
did you reset W10?

No,
Unplugging electrically means cutting off all electrical contact, charger and battery.
Then press and hold the power button for a minute without releasing it.
Reconnect the charger.
Try it.

Rolling back to a previous version won't work because the one-month deadline
has passed,
You can:
1-try resetting W10 again
2-try reverting to a previous restore point
3-reset W7 to factory settings
These three options have very little chance of success but can be attempted if you have time,

There is still;
4-Reinstall W10 with the DVD,
You can download the ISO from the internet for free and burn it to a DVD or USB stick,
5-Reinstall W7 with the DVD, if you have it, otherwise it’s not easy to find but it is available,

If you like W10 that would be the easiest solution, normally reinstalling with the DVD should work much better than during a migration,

Think about it and I will tell you how to proceed,

If you want to recover your data, that's also possible.

Can you give me the reference of your PC?
The restoration (or reset) to factory settings restores the PC to how it was on the day of purchase.
This function exists on brand-name PCs.
It uses a partition called recovery of about fifteen gigabytes.
You need to press a key at boot, it depends on the PC.
It should be the key you mentioned.
But during a migration to W10, this tool is often erased and the reset concerns W10 and later, not W7.
That's why it might be worth a try, but if you already reset it
it's because W10 erased that possibility.
Did you not create a system backup when you were on W7?

If you do not have the installation file for your version of W7, the easiest way for you is to reinstall W10 with a USB drive.

Did you put W10 on the USB stick?
It's not normal that you can't install W10, it looks like the hard drive is inaccessible.
You can try to make a bootinfo report with boot repairdisk.
Post the link.
To see if the internal hard drive shows up.

Download bootrepairdisk and put it on a USB stick to boot from it.
For that, you can use Rufus, just show it the path to the ISO and it will prepare the bootable USB stick.

https://doc.ubuntu-fr.org/boot-repair

https://www.winmacsofts.com/rufus-creer-une-cle-usb-qui/

I don't understand why you're on the command prompt.
Is this what you're talking about:
http://www.google.com/...

Did you manage to put Windows 10 on the USB key with Media Creation Tool?
If so, you can download UBCD, just ignore the boot repair.
You need to put UBCD on the USB key with Rufus, if you can't do it, let me know.
When you've done that, I'll post to tell you how to check the hard drive.

https://www.commentcamarche.net/telecharger/utilitaires/22571-ultimate-boot-cd/

The Media Creation Tool is used to either install Windows 10 on the PC it is running on or to create a USB flash drive or a DVD containing Windows 10 to install it on another PC, which is your case.
You should not put the Media Creation Tool on the USB drive but transfer the Windows 10 installer to the drive using the Media Creation Tool.
Then, once that’s done, you start the PC to be repaired and quickly tap the F12 key
which will open a boot menu where you can select the USB drive and press Enter to launch the installer; sometimes it asks you to press any key at that moment, which you should do.
Try checking by right-clicking on the USB drive that you connect to your working PC and looking in Properties how many gigabytes the drive is in terms of storage used.
If it shows 3.3 gigabytes, it means Windows 10 is on it.

Here’s how to recreate the drive if you didn’t succeed the first time.

Here’s how to download the Windows 10 ISO.
Go to this page:

https://www.microsoft.com/fr-fr/software-download/windows10

Click on: Download tool now.
Save and run MediaCreationTool.exe
Accept the agreement.
Create installation media for another PC
Next
Uncheck: Use the recommended options for this PC
Next.

Follow the instructions to place the installer on the USB drive.

Right-click on the USB stick, properties, there check the usage of the drive if it approaches 3.3 gigs.
You can try to redo it, maybe W10 downloaded incorrectly or something else.
Do you have any other USB sticks?
Normally, the stick should start the installation program by doing what you're doing, there must be a defect, redo it otherwise we're going to go in circles.

This USB key is one that should present an installation program; if you boot from it and that program doesn't open, there's still a good chance it’s due to the key being improperly configured.
It's a bit foolish not to redo it because if the issue arises from it, you can run all possible hard drive tests, but that's not going to give you a proper Windows 10 installation.
What do you risk by starting the process over, at this point?
If that's not it, we can take a look at the hard drive afterward.

Hello.

Summary:

Here’s how to recreate the key if you didn’t succeed the first time.

Here’s how to download the W10 ISO.
Go to this page:

https://www.microsoft.com/fr-fr/software-download/windows10

Click on: download the tool now.
Save and run media creation tool.exe
Accept the agreement.
Create installation media for another PC
Next
Uncheck: use recommended options for this PC
Next.

Follow the prompts to put the installer on the USB key.

Then, once this is done, start the PC to be repaired and quickly tap the F12 key
which will open a boot menu where you can choose the USB key and press enter to launch the installation program; sometimes it asks you to press any key at that moment, which you should do.

It should open an interface that looks like this:

http://www.windows8facile.fr/installer-windows-10/

To recover deleted files, there's Recuva.
But they shouldn't have been overwritten by multiple successive writes.
The program didn't warn you that the drive was going to be formatted?

https://www.commentcamarche.net/telecharger/utilitaires/19127-recuva/

What error message appears and when does it occur?

When?

0xc000021a may indicate that there is a memory issue.
Did you manage to boot from the USB drive?

But well, what does that mean?

Well, it's installed but I can't access the Windows desktop; instead, it displays what I sent you earlier.

This displays: 0xc000021a ?

If that's the case, you can test the memory in the way described here with UBCD that you put on a USB stick using Rufus:

https://www.pc-infopratique.com/forum-informatique/windows-8-0xc000021a-vt-72613.html

https://rufus.akeo.ie/

No.
It's better for you to get another key.

https://www.commentcamarche.net/telecharger/utilitaires/22571-ultimate-boot-cd/

The only thing to do in Rufus is to indicate the path to the UBCD ISO by clicking on the disk represented next to the 'create a bootable disk' line, after inserting your key into the PC.
Then click start.

The path is the location where the UBCD ISO is located; it may be in downloads.
If that's the case, you click on the drive in Rufus, go to downloads, and then select the ISO.

Hello.

You insert the USB drive or CD containing UBCD into the PC.
You restart and immediately press F12 like for the installation of Windows 10.