I had this problem and tried all methods all over the internet and couldn't fix it for months. But I used some other methods to fix it
METHOD 1:- [WHEN YOU CAN BOOT INTO WINDOWS]
You can also use the windows ISO which you already have with you but the condition is if you want to avoid data loss then you'll have to use the same version of windows ISO which you have installed or the latest version OF windows ISO but you should not use an older version of windows ISO. If you don't have a windows ISO then you can download it from any one of the below links.
//tb.rg-adguard.net/public.php
You can also download windows ISO from the below site too
//tb.32767.ga/
Now mount the windows ISO image and copy the contents of the ISO to some other drive except your C: drive
go to start menu and open Command prompt as administrator.
Now type "CD /d [location of windows 10 setup files]" and hit enter.
Now you can use which ever command you want based on your requirement. just type anyone of the below commands in CMD and hit enter.
setup.exe /auto upgrade /dynamicupdate disable /showoobe full - This command will keep your personal files and Apps.
setup.exe /auto dataonly /dynamicupdate disable /showoobe full - This command will remove your apps but keeps your personal files
setup.exe /auto clean /dynamicupdate disable /showoobe full - This command will clean install windows
6] It will take about 50 minutes to get completed.
METHOD 2:- [WHEN YOU CAN BOOT INTO WINDOWS]
Mount and copy [or] extract the ISO to a location other than you C: drive
go to start menu and open Command prompt as administrator.
Now type "reagentc /info" and hit enter
Then type "reagentc /boottore" and hit enter
Now restart your computer. your computer will automatically boot into recovery environment the next time you restart your computer.
Now click on "troubleshoot" then click on "advanced options" next click on "command prompt".
Now type "notepad" in the command window.
Then go to file and click on "open"
Click on "this PC"
Now select "all files" from the files of type drop down menu at the bottom.
go inside the drive in which you extracted or copied the setup files
Then right click "setup.exe" and click on "run as administrator".
go ahead and format the C: drive and install windows.
METHOD 3:- [WHEN YOU CANNOT BOOT INTO WINDOWS]
Download RUFUS from the below links
//rufus.ie/
Open RUFUS and first select your USB drive
Then click on "select" and select the windows ISO File
Then press "Alt+E" to enable dual boot mode
Then select FAT32 from the "File system" drop down and click on "start" and click on "OK"
After it gets completed click on "Close" and insert the USB in the PC which you want to reset
Power ON your computer and when you see windows logo long press the power button and turn turn it OFF [Repeat this 3 to 4 times]
the next time when you turn ON your PC you'll see automatic repair screen and diagnosing your PC screen. then click on "advanced options"
Click on "troubleshoot"
Then click on "advanced options" again
Now click on "command prompt"
Type "notepad" and hit enter
Then go to file and click on "open"
Click on "this PC"
Now select "all files" from the "files of type" drop down menu at the bottom.
Copy the files whichever you want from C: drive to some other drive because this process will clean install windows
Now close windows dialog box & notepad and then type the below command in command prompt and hit enter
wmic logicaldisk where drivetype=2 get deviceid, volumename, description
18] This will show you list of USB devices and there drive letter
19] Type the drive letter of your USB followed by a colon and hit enter
20] Then type "setup.exe" and hit enter
21] This will bring up windows setup
22] Click on "next" and go ahead and format your C: drive and install windows
For better explanation you can watch this video
//youtu.be/5p7P1JnViWU
Under certain hardware configurations, when attempting to Reset this PC on a system running Windows 10, build 2004, the reset attempt fails with the following error: There was a problem when resetting your PC. No changes were made. As a workaround for this issue, do this: Open an elevated command prompt. To do this, click Start, type Command Prompt or cmd in the Search box, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.Symptom
Workaround
Type the following command, and then press Enter:
dism /online /cleanup-image /restorehealth
Reboot your system, and attempt Reset this PC again.