Hello, IT-Premsagar.
Welcome to Microsoft Community!
I noticed that you reset this Surface Pro 5 in order to improve the performance of the device:
Restore or reset Surface for Windows - Microsoft Support ****
After the reset, you noticed that it automatically installs some apps, but the Windows Hello feature no longer works and perhaps you were able to access this device by entering a PIN.
In fact, the reset does install apps that are necessary for the system. If you think there are any suspicious apps, you can let us know in the form of an image.
If we are still in a position to operate, you can try to manually obtain the driver and firmware installation package for Surface Pro 5 to troubleshoot potential driver issues and maintain device performance:
Download Surface Pro 5 [Wi-Fi] Drivers and Firmware from Official Microsoft Download Center ****
Reboot this device after the download is complete to apply the driver update. The above steps usually work if the issue stems from the driver.
If your Windows Hello is still not working correctly, I urge you to try resetting the device completely with the help of a USB recovery drive. This operation works even if you don't have access to the device. I will share a complete step-by-step procedure with you:
(If you have anything to back up, please try to back up.)
Please visit the following site to get the image file for Surface Pro 5:
Surface Recovery Image Download - Microsoft Support
Get it by logging into your account and entering your device's serial number:
After completing the creation of the recovery drive, continue to refer to the guidelines in the following link to complete the recovery operation:
Creating and using a USB recovery drive for Surface - Microsoft Support
The link shows us a complete demo video and key textual guidelines:
Through the above steps, we were able to restore the device to its original state. See if Windows Hello functionality is restored.
I am here to support you.
Best Regards.
Leo.L - Microsoft Community Support Specialist