Windows 10 login screen has become very slow since recently

I haven't noticed when exactly I started observing the extreme slow down of the Windows 10 login screen on my laptop.

Sometimes, this screen is fast as it was normally; but once in a while after pressing the power button I have to wait about 5(!) minutes staring at pre-login screen. I apologize for phone made images of the screen.

In addition to that, the responsiveness has decreased dramatically. The reaction to button press is delayed by approximately 1-2 seconds!

After I enter my 4-digit PIN-code, I wait for about another minute for the Desktop to appear... What on Earth can cause that and where do I start troubleshooting? I inspected the Task Manager for any CPU hungry processes and disabled Windows Defender (yes, I know...) which was consuming a LOT of resources. That did not help much...

• I am not 100% sure, but I think that the extremely slow logins happen after my laptop is asleep for more than 4-6-8 hours ("deep hibernation" may be?) If I put the laptop to sleep and come back within an hour, it usually behaves nicely.


• The laptop is roughly 5 years old: Samsung XE700T1C-H01RU
  
  
  
  • Intel i5-3317U, 2 cores @ 1.7GHz
  
  
  • 4 GB DDR3 RAM @ 1600MHz
  
  
  • Samsung MZMTD128HAFV 128Gb SATA Gen3 / mSATA 6Gbps SSD
  
  
  
  


• When login is slow, after-login experience are slow as well for a few minutes. In less than 5 minutes the machine is fully functional again.


• I could not directly associate slow logins to any OS update related activities, but that's not easy to do in the first place.


• winver: Windows 1607 OS Build 14393.1884

Update 1 QuickSearch shows that there are many more users on 1607 version who experience same issue.