If Windows asks whether you want to allow Regedit to modify your computer, say Yes.
Navigate from HKEY_LOCAL_MACHINE to SOFTWARE, Policies, Microsoft, Windows
Right-click the "Windows" folder and choose New, Key. Name the key "Personalization".
Right-click your the newly-created Personalization key, and choose New, DWORD (32-bit) Value.
Name the DWORD value "NoScreenLock".
Double-click the value to edit it, and change it from 0 to 1.
Click OK to save the value and verify that everything is spelled correctly and that the value now shows as 1.
Close Regedit and reboot the PC. The lock screen should now be gone.