There are several different things happening here: device registration, account type restrictions, and Windows Hello PIN prompts.
- Why the Lenovo device disappeared and cannot be added
For Windows 10/11:
- Windows PCs are normally added automatically to a Microsoft account when signing in with that Microsoft account on the device.
- A device may not appear or may disappear from the devices list if:
- It is already registered to another Microsoft account.
- The PC is managed or owned by an organization (work/school) and therefore cannot be registered to a personal Microsoft account.
From the documented causes when a device cannot be added:
- macOS or mobile devices cannot be added at this time.
- If the PC is managed or owned by a company or organization, it cannot be registered to a personal Microsoft account.
- A device can also already be added to another account.
- It can take up to 24 hours for a registered device to show on the list.
To check and manage devices:
- Sign in at https://account.microsoft.com/devices with the intended Microsoft account.
- Confirm whether the Lenovo PC appears there.
- If it appears under a different Microsoft account, sign in with that account and use Remove device if the PC is no longer supposed to be associated with it.
- Then sign in on the Lenovo with the correct Microsoft account; Windows 11 should automatically add it to that account.
If the PC is joined to a work/school organization (Microsoft Entra / Azure AD), it may be restricted from being registered to a personal Microsoft account. In that case, the organization’s policies control the device registration.
- Message about only being able to use work/school account
When adding accounts in Windows, there are two different flows:
- Adding a work or school account (for organizational resources and device management).
- Using a personal Microsoft account (Outlook.com, Hotmail, etc.) for Windows sign-in and Store.
If a page says that only a work/school account can be used, that is the Entra (organizational) registration flow. In that flow:
- Selecting Yes on the Entra account registration page:
- Registers the device in the organization’s directory.
- Makes the account available to desktop and web apps that use the work/school account.
- Selecting No, this app only signs in only to that app and does not register the device.
If a Yahoo address is being used, it can be:
- A personal Microsoft account alias (if previously set up), or
- Just a non-Microsoft email that is not a valid work/school account in Entra.
If the system says the Yahoo account cannot be used in the work/school account flow, that is expected; only organizational accounts are accepted there. Use the Outlook-based Microsoft account (or another Microsoft account) for Windows sign-in and device registration instead.
- Being forced to set up a 6-digit PIN instead of using password
On Windows 10/11, when signing in with a Microsoft account, Windows Hello PIN is strongly encouraged and sometimes required by policy:
- The PIN is stored locally on the device and is used instead of the online account password for sign-in.
- Organizations can enforce PIN setup when a work/school account is added and the device is registered/managed.
If the device is registered to an organization (Entra registered or joined):
- The organization may require Windows Hello for Business, which forces PIN setup.
- In that case, the prompt to set a 6-digit PIN cannot be bypassed if the policy is enforced.
If the device is personal and not supposed to be managed by an organization:
- Go to Settings > Accounts > Access work or school.
- If a work/school account is listed that should not manage the device, select it and choose Disconnect.
- After disconnecting, sign out and sign back in with the personal Microsoft account; this may reduce or remove enforced PIN requirements, depending on policies.
If the device was accidentally registered to an organization by selecting Yes on the Entra registration page, disconnecting the work/school account as above will stop that management and may change the sign-in behavior.
- Removing a work/school account and reverting to personal sign-in
If a work/school account was added and is causing management or sign-in changes:
- Open Settings > Accounts > Access work or school.
- Select the work/school account and choose Disconnect.
If the Microsoft account was linked to the Windows profile and the goal is to use a local account instead, the documented pattern is:
- In Settings > Accounts > Your info, there is an option Sign in with a local account instead (when available). Using that will switch the device back to a local account sign-in and remove the Microsoft account from being the primary sign-in identity.
- Summary of practical steps
- Verify device registration:
- Check for organizational management:
- On the Lenovo, go to Settings > Accounts > Access work or school.
- If a work/school account is present and should not manage the device, select it and Disconnect.
- Use a Microsoft account (Outlook-based) for Windows sign-in and device registration, not the Yahoo address in the work/school account flow.
- Accept that a PIN may be required if organizational policy is applied; if the device is personal, removing the work/school account and using only a personal Microsoft account may reduce that requirement.
References: