PxTools Pin to Taskbar issues in Windows 10

Last year in Px Tools 3.4.2 I implemented some “experimental” tasks, to test a variety of situations. One of those was ManagePinnedShortcut_Ex, which gave us back the Pin to Taskbar functionality in Windows 10 that Microsoft had blocked. This solution was somewhat… kludgy, but it seemed to work without side effects.
A few weeks ago a new customer reported some odd behavior. Prior to any Px Tools PinToTaskbar shenanigans Windows 10 Default Apps might look like this:

After any PinToTaskbar in Windows 10, they had this.

I think we can agree that’s… shitty. And, while I hadn’t heard from any other customers, and I specifically pinged Aaron Maller about it, I COULD recreate the situation on my own test VMs.
For 3.4.2 I had modified an implementation of PinToTaskbar that I had found on StackOverflow, and I hadn’t fully understood what it was doing. In one place it had a somewhat overzealous cleanup. Basically the implementation creates a new key, subkey and property in the registry to get the hack to work. It then Deletes that new key and everything in it, which seems safe enough, we just created it seconds before to implement our little hack. But, somehow once that key is created (HKCU:\SOFTWARE\Classes\*\shell for those that are curious) it can, sometimes, cause havoc with Default Apps to delete it. So I addressed the issue by not deleting the shell key, but only the PxToolsWin10PinToTaskbar subkey and the ExplorerCommandHandler property in it. This was delivered in Px Tools 3.4.3 last week. Then, yesterday I heard from another customer who is now seeing the same behavior! So glad I hadn’t delayed implementing the fix!
Given that it isn’t happening to everyone, and only just started to happen to anyone, I assume it is related to a recent Windows Update. I have verified that it is not limited to a single build of Windows 10, at least 1703 & 1809 are affected. But it is happening, and it seems to be spreading, and thus the urgency to get this BLOG post out.
To add even more fun, 1903 again totally blocks Pin to Taskbar, but that is a problem to be solved then talked about in another BLOG post. 🙂

So, if you are on Windows 10, and are making use of Px Tools Pin to Taskbar, I strongly recommend you upgrade to Px Tools 3.4.3, and NOT upgrade to Windows 1903. On the latter, it seems that even Microsoft has seen the light as far as forcing new Windows builds on us, and made this one optional. But, you may need to check with IT to make sure that it doesn’t get installed automatically anyway. In addition to the Pin to Taskbar issue, at least Inventor 2016 & 2018 are also having some issues. That alone would give me pause on upgrading.

So, hopefully this saves someone some grief. And hopefully getting Pin to Taskbar working in 1903 is not too difficult and I have learned enough to do it without side effects the first time. So with that, back to work!