This isn't really helping as much as adding my info and some of my thoughts to the pile:
I have the same issue, and just went into the windows folder on my HD and the "winstore" folder doesn't exist in C:\Windows, and was not found using the folder search (thus was not found in any sub folders). Not claiming to be an expert and have not done
an exhaustive search through all files/folders (including hidden ones) but it seems that somehow the windows store got moved or deleted.
I will note that this started for me this morning (Sunday, 3/18/2018) after I fully powered down my computer last night. Previous to that it had not been restarted or powered down since Friday, when I attempted to re-install some windows98 and XP era games
(they ran), but in the middle of working with those, two windows updates installed: KB4090914 (Update for Microsoft Windows) & KB4088776 (Security Update for Microsoft Windows).
For what it's worth, everything in my system that doesn't deal with the windows store, windows update (this set of options is completely missing from the control panel), or the task bar appears functiona: File explorer, powershell and command line all still
seem to work, so do Mozilla, and my games that don't use the store, as well as Microsoft Office programs... Everything I have been able to go find a .exe file for.
I can also still access things like the control panel and all the settings that are currently otherwise unavailable (since they seem to be tied to whatever is missing) by holding the windows key, and pressing r, then typing "control" without quotes. It
opens the control pannel for access to settings and where you can eventually navigate to see things like when updates were installed, etc.
Maybe somebody else can find the source of this or some neat way to reinstall the store (and Cortana apparently?) But other than that right now it's looking like a reinstall is going to be the only way.
This sounds like the same problem I have been experiencing. I also cannot run WSReset.exe. When I try the cursor moves down a line a starts blinking. Even after a long wait nothing happens. I even tried to copy the file from another computer and run it but
get the same result. would love to solve this but are waiting for the next major update hoping it will solve the problem.