Friday, 7 August 2020

The Ultimate Lockdown?

Now we all like IT stories of stupid users. We also like stories of weird and unforseen disasters. Finally everyone likes a good cautionary tale. Well this one is all three...and the stupid user was me.

A while ago my Microsoft Natural PS/2 keyboard went wrong. Luckily I had Natural Keyboards on both our PCs (because being a touch-typist I find them easier to work with). The second PC has now become my daughter's PC, and she let me swop her keyboard for a standard USB one while I sourced a replacement. She wouldn't let me keep it, because she is used to the "split" keys and like me, now dislikes the ordinary layout.

It appears that PS/2 Natural keyboards are almost impossible to find now, so I had to go for a brand new Microsoft Ergonomic USB keyboard, which I didn't like as much because it was black, and I can't see the keys as well. Ho hum. [Note the significance of USB]

Anyway, it looks like my department will be "working from home" for the foreseeable future, so today I dropped in and picked up my work keyboard (which happens to be a beige Microsoft Natural PS/2) and brought it back home with me. At last I could go back to a lighter keyboard that I can actually see. Yay!

So I plugged it in, and booted it up...and it didn't work. After much Googling I found out the reason. When you plug a new MS Ergonomic USB keyboard in, Windows 10 does two things:

1. It downloads a new version of the keyboard driver, to support the enhanced capabilities of the new USB Microsoft Ergonomic Keyboard hardware.

2. It disables the old PS/2 keyboard by changing a Registry key from 1 (Start up at Boot) to 4 (Disable)

So now I knew the reason, and a tech discussion on a web page advised that all you needed to do was change the USB keyboard's setting to 4, and the PS/2 keyboard's setting back to 1, and then reboot. What could go wrong? A couple of Registry changes and I rebooted the computer. End of story.

Unfortunately it was not the end of the story. Can you guess what happened next? Of course you can. But I'll explain why. You see the new keyboard driver doesn't support the old MS Natural PS/2 keyboard any more, because it has overwritten the old driver (which did).

[Yes I know some of you may be thinking "I've swopped between PS/2 and USB keyboards before, I never had this problem!". It's the new USB version of the Microsoft Ergonomic (née PS/2 Natural) Keyboard that has this issue, not standard PS/2 and USB.]

Anyway, so what happens when Windows boots up? The USB keyboard is disabled, so it doesn't work. The PS/2 keyboard tries to load up, but fails because the new keyboard driver no longer supports it. So I'm faced with a Windows logon screen and no way to type my password into it. So I can't get into Windows to change the Registry settings back! I'm permanently locked out of the computer in the most stupid way possible.

Luckily of course there was a way out of it. Well actually two. If you have an old standard USB keyboard, you can plug that in and reboot, and you will be able to type, so you can reverse the damage to the Registry. I used the second method, which was to access the PC through a remote desktop session from another PC.

Of course if you have only 1 PC, and no spare're screwed.

Be warned!

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