I need to reset guest key but I don’t know the password

If you are referring to the guest key, check this out:
support.xbox.com/.../forgot-guest-key

A forgotten guest key can be reset by any adult as long as that person knows the password that they use to sign in to their Microsoft account on the console. The adult must be signed in on the console to reset the guest key.

A forgotten guest key can be reset by any adult, as long as that person knows their Microsoft account password and is signed in on the console.

1. Follow the steps to remove a guest key.
   
2. When you’re prompted to enter the guest key, enter an incorrect key three times, and then enter your Microsoft account password to remove the guest key.
   
3. If you want to create a new guest key, select Create a guest key and follow the steps.
   

In your case, since you deleted your Microsoft account, I would recommend creating a new one as that would be the only option!

Hello NikkiKruik,

Thank you for keeping us updated. A forgotten guest key can be reset by any adult, as long as that person knows their Microsoft account password and is signed in on the console.

1. Follow the steps to remove a guest key.
2. When you’re prompted to enter the guest key, enter an incorrect key three times, and then enter your Microsoft account password to remove the guest key.
3. If you want to create a new guest key, select Create a guest key and follow the steps

Those would be the only steps for forgotten passkey that we have on the support article linked above. At this point, please follow the steps in the second link above for a factory reset. I'll go ahead and link it here for you as well: Factory
reset

Hey there Grave,

Sorry to hear you are running into this problem. You should be able to reset the Guest Key, When it's asking for the Guest Key go ahead and enter it wrong 3 times. After this it should ask you for your password.

Give it a try and let us know if this works.

Sign into the main account for the Xbox, and follow these steps. When it asks your to enter the guest key, give it three tries. After the 3rd failed try you will be asked to enter your Microsoft password linked to that account.
If this does not work, you will need to do a hard reset sadly.

Remove Guest Pass:

• Sign-in with your account on Xbox One.
• Press the Xbox button to open the guide > Settings > System > Signed-out content restrictions.
• It will ask you to enter your Microsoft account password to confirm your identity.
• It will then ask you to enter the guest key to remove it.
• You can also try entering an incorrect guest key three times, and then it will prompt you to enter the Microsoft account password to remove it. This will remove the guest key.
• If you remember it correctly, you will directly get an option to Remove guest key.
• You can then go ahead, and create a new key with new restrictions.