computer is locked

Hello Kavita Kushwaha

With regards to this computer lock issue that you are seeing on your screen, this occurs due to a multiple incorrect login attempt caused by a recent password change on the account. Refer to this KB https://support.sophos.com/support/s/article/KB-000035365?language=en_US and apply steps being described to solved the issue. 

I would also suggest a FULL shutdown of the PC too - not just the standard one that doesn't really shutdown as such. You should also still be able to log in with the Windows Credential provider (the "normal head/shoulders" icon) once the device is fully shut down.