If Get-AppxPackage -AllUsers "*Store*" returns nothing then it is completely removed from your system. If this folder is missing
Microsoft.WindowsStore_11602.1.26.0_neutral_split.scale-100_8wekyb3d8bbwe from C:\Program FIles\WindowsApps, then you can't install the store. You could try copying the folder from another system and then rerun the first command I listed. The other option is to completely wipe out your Windows install and start with a clean install.
WindowsApps is a hidden folder, it also doesn't allow for browsing to it from explorer by default, but you should be able to navigate to it from an elevated powershell or command prompt.
Code:dir /A:DH "C:\Program Files"
You probably won't be able to see the content of WindowsApps but if you CD to the folder first then just type dir you should see the content.
That means the folder is empty or the data is hidden. You will either need to get the requried folders from another computer or re-install windows.
I would just copy everything in the WindowsApps folder and when you copy over you can just skip any duplicates. After you copy it over run the first command from reply #8. If you open explorer (the file/folder browser) [Windows key + e] and go to view > settings you can uncheck the "Hide hidden file/folders" then you should be able to copy it.
Maybe I can do it using cmd?? xcopy (source) (destination) \e\s\h ?? Something like this...You may not be able to copy them. It sounds like it may come to doing a clean install of Windows.