Hi AjiBade,
This issue may be due to recent changes made on your Surface and it sounds like you had previously created a Password Reset Disk. Do you have this USB disk available to use to reset the password?
If not, if you're on Fall Creators update, you can try to reset your PIN from the Lock screen. Here's how:
- In the Lock screen, click the I forgot my PIN link. (If you have multiple accounts, make sure to select the correct account first.)
- Type your Microsoft account password.
- Click Next.
- Select the recovery email address from the drop-down menu.
- Complete the hidden part of the email challenge.
- Click Next.
- On your phone or using another computer, using the recovery email account check for the Microsoft account code and enter it to verify your identity.
- Click Next.
- Click Continue.
- Set up your new PIN.
- Click OK.
Once you've completed the steps, you'll be back on the sign-in screen, where you can use the new PIN to unlock your device. If the password reset option isn't available on the Lock screen, it's likely because you're not running the Fall Creators Update yet.
You can find additional steps at Reset your Windows 10 local account password.
If you weren't able to reset the PIN and still can't login, we recommend that you contact our Answer Desk for assistance. Let us know if you have any additional concerns.
Regards.