You cannot bypass the former administrator’s password or simply promote yourself from a standard account; preserve any needed data through authorized recovery first, or erase and reinstall Windows to create your own administrator account.
If you need files from the computer
Do not reset or reinstall Windows yet.
- Identify the account type on the sign-in screen.
- If the account name is an email address, it is probably a Microsoft account. Select I forgot my password, or use Microsoft’s password-reset page from another device—but only if you are legally authorized and can complete the account’s identity verification. ^1^
- If it is a local Windows account, enter an incorrect password, select OK > Reset password, and answer the security questions. A previously created password-reset USB can also be used. ^2^
- If BitLocker requests a 48-digit recovery key, stop until the key is located. It might be stored in the Microsoft account used to configure the computer, on a printout, or on a USB drive. Microsoft cannot recreate a missing BitLocker key; resetting without it removes the files. ^3^
- For access to your son’s Microsoft cloud data, such as OneDrive or Outlook.com, use Microsoft’s deceased-user process. Access may require legal guidance and a valid subpoena or court order, and access is not guaranteed. This process concerns the Microsoft account and cloud data; it does not directly make you a Windows administrator. ^4^
Microsoft Support cannot retrieve or circumvent a forgotten Windows password. ^2^
If the files are not needed and you only want to reuse the PC
Reset Windows and create your own account during setup:
- Start the PC and interrupt startup twice by holding the power button while Windows begins loading.
- On the third start, enter Windows Recovery Environment.
- Select Troubleshoot > Reset this PC.
- Choose Remove everything, then follow the prompts.
- When Windows setup starts, create your own user account; that account becomes the administrator for the newly configured PC.
Remove everything permanently deletes personal files, applications, accounts, and settings. Resetting reinstalls Windows but does not grant access to your son’s Microsoft account or encrypted data. ^5^ The deceased-user case guidance specifically recommends keeping nothing when account recovery is not possible. ^6^
Although Windows may display Keep my files, do not rely on that option in this locked-account situation: it may require credentials you do not have. If preserving files matters, return to the recovery options above instead.
If Reset this PC is blocked or fails
Perform a clean installation:
- On another working computer, obtain Microsoft’s Windows 10 Media Creation Tool from
https://www.microsoft.com/software-download/windows10 - Insert an empty USB drive of at least 8 GB and use the tool to create Windows installation media.
- Boot the locked computer from that USB drive. The manufacturer’s boot-menu key varies by model.
- Choose a clean/custom installation and complete Windows setup.
- Create your own account during setup.
A clean installation erases the existing Windows installation and its data. It prepares the computer for reuse; it does not recover the deceased user’s account or encrypted files. This is the applicable fallback when an administrator password prevents the reset. ^6^
References
- Change or reset your Microsoft account password in Windows | Microsoft Support
- Change or reset your local account password in Windows | Microsoft Support
- Find your BitLocker recovery key | Microsoft Support
- Accessing Outlook.com, OneDrive and other Microsoft services when someone has died | Microsoft Support
- [Windows 10](https://support.microsoft.com/windows/experience/backup-recovery/reset-your-pc#reset-your-pc-from-windows-re)
- How to access deceased fathers account - Microsoft Q&A