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.
Here are all the results of which you said: Untitled — Postimage.org
Get-AppxPackage -AllUsers "*Store*" doesn't return anything as you say. Also sfc /scannow says that there are corrupt files but windows is unable is fix those.
Also there is no folder like WindowsApps in C:\Program Files\ in my PC. Microsoft.WindowsStore_11602.1.26.0_neutral_split.scale-100_8wekyb3d8bbwe is a far thing.
So what shall I do finally?
Edit: This is what I get from that DISM command: Untitled — Postimage.org
Also you mean in win10 I should search .appx ?