When you perform a factory reset on a Windows 10 phone, the PIN code will be removed along with all other personal data, apps, and settings. The phone will return to its original state, just like when it was first turned on.
However, there's one important thing to keep in mind:
Factory Reset Protection
After the reset, the phone may still ask for the Microsoft account credentials that were previously used on the device. This is a security feature to prevent unauthorized access.
So even though the PIN is gone, you'll need to sign in with the same Microsoft account to complete setup. If you remember your account email and password, you're good to go.
Let me know if you’d like help walking through the reset steps or checking if your account is ready