Hi,
At this point, I recommend we boot into WinRE and enable the build-in administrator account, then change the password for your local account.
Boot from Windows 10 installation media and then choose Repair your computer link. In WinRE, under Troubleshoot\ Advance options, choose Command prompt.
1. Now run “regedit” from the command prompt.
2. Click on HKEY_USERS and then click on File > Load Hive

3. Navigate to D:\Windows\System32\Config folder and select the SAM file then click Open
4. Now type “SAM_TEMP” (or any value) in the Key Name text field and click OK

5. Expand SAM_TEMP\SAM\Domains\Account\Users\000001F4 and double click on the “F” key.

6. Change the value “11” in the first column, row 0038 to “10” and click OK
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7. Click back on “SAM_TEMP” and then from the File > Unload Hive and Yes to confirm.

8. Exit Regedit and close the Command Prompt and click Continue to exit Windows 10, you will see Administrator on Logon screen.
The default password could be empty if you haven't set before in Windows 10, otherwise, you should know the password of it.
The, we can add your current account into Administrator group.
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