I've had a few people come to me worried that their windows login is now blurry.
Most have had no reason to worry and explaining this as a new design feature of Windows 10 leaves them a bit confused but happy that nothing is wrong.
This isn't for everyone, so if you want to turn it off click on the picture below for a bunch of ways to do that.
However, some people have got stuck at the blurriness and been unable to do anything else.
That IS an actual problem.
If you click to login the way you used to and all you see is a blurry image i.e. no login, no way back, no buttons etc. and all you can do is select Reboot/Shutdown/Sleep, then yeah...you have a real problem.
This failed login problem is quick a painful. No amount of "Start up Repair" or "System Restores" will fix it.
It is worth noting that, at this stage, I found that using the <SHIFT> Reset selection also FAILED to get me into the start up options screen (and hence Safe Mode).
So you may want to avoid wasting time on that one and move straight to the alternative ways to get into Safe Mode.
Read my blog post here to find out how to do this: https://www.ihatemypc.com.au/post/what-s-your-safe-word
Hint: It is option "2. Interrupt the normal boot process of Windows 10 three times in a row" is the go-to replacement for being able hit (SHIFT) F8 at boot-up time.
When in safe mode you'll need to do the procedure outlined here: https://answers.microsoft.com/en-us/windows/forum/all/pc-stuck-at-a-blurry-login-screen/b63b7722-41ef-4cfa-9220-b3609452f8a0
It is worth noting that, in that procedure, where it says %windir% that that may not work for you.
But don't stress, %windir% is a variable that contains the location of your windows directory and, funnily enough, that is pretty much always just C:\Windows. [NOTE: if it isn't, you don't need my help explaining this. You already know what you are doing ;-)]
So where you see something like this:
Open File Explorer and browse to %windir%\system32\config
You can safely assume this is where you want to go: C:\Windows\system32\config
Similarly, but notably different, the %localappdata% system variable may need replacing.
So where you see something like this: %localappdata%\microsoft\windows\caches
You'll need to go to the folder named LIKE this: C:\Users\David\AppData\Local\Microsoft\Windows\Caches
The important difference is that the folder is almost certainly going to be different for each person and sometimes it isn't on the C: drive either!
It is the user's own folder and, as you can see for mine, my name is in the folder path.
You'll need to put your name there or the title/ID of the login on that machine. It isn't always a person's name.
Once you've followed this procedure through the machine should boot up normally and let you get past the login blurriness.
IMPORTANT: If your login procedure, prior to this problem occurring, did NOT require a password and you just automatically logged in to the desktop, then I strongly recommend you ADD A PASSWORD. This issue seems to at least be partially caused by that process. These days you really should have a password anyway.
IMPORTANT 2: While not directly related to this issue, once you machine is OK you should check the amount of space your System Restore function has been allocated. If it has not been turned on or the allocation is 0 (zero) then you should read the article here to turn it on and allocated 5% of your disk space to the job (as a starting point). Create a restore point right away.
David (maybe you can see me if you squint?)