Hello, Rahul Solanki1
Welcome to the Microsoft community.
Thank you for your feedback. I understand that you are experiencing a problem with forgetting your password. Based on your description, you can only try to reinstall windows using USB installation media. You may refer to the following link:
How to: Perform a Custom Installation of Windows 11 and Windows 10 - Microsoft Community
For file backup, you can refer to the following link:
Rescue Files when Windows Won't Start - Microsoft Community
I look forward to your feedback.
Best Regards,
Aaron| Microsoft Community Support Specialist