Windows store is using the same process as what Windows usually use to perform Windows update, to download and install the applications. To restrict this process will cause an issue in the automatic Windows update, which will mean that everything updated by Windows will not be trusted. This may cause the OS unable to run properly because the new files will get blocked. Even let's say if we are able to restrict the process, there will be an issue in how to trust the files that download by Microsoft Store. According to our observation, currently the applications are stored at C:\Program Files\WindowsApps forlder. This folder is protected by Windows. If you are trying to access this folder from Windows Explorer, you will get access denied.