disable the ability to install in admin mode

Bloxstrap/App.xaml.cs

@@ -138,6 +138,14 @@ namespace Bloxstrap
 
             Paths.Initialize(BaseDirectory);
 
+            // disallow running as administrator except for uninstallation
+            if (Utilities.IsAdministrator && !LaunchSettings.IsUninstall)
+            {
+                Frontend.ShowMessageBox("Bloxstrap does not support running in administrator mode. Relaunch or reinstall Bloxstrap with lower privileges.", MessageBoxImage.Error);
+                Terminate(ErrorCode.ERROR_INVALID_FUNCTION);
+                return;
+            }
+
             // we shouldn't save settings on the first run until the first installation is finished,
             // just in case the user decides to cancel the install
             if (!IsFirstRun)

Bloxstrap/Enums/ErrorCode.cs

@@ -8,6 +8,7 @@
     public enum ErrorCode
     {
         ERROR_SUCCESS = 0,
+        ERROR_INVALID_FUNCTION = 1,
         ERROR_INSTALL_USEREXIT = 1602,
         ERROR_INSTALL_FAILURE = 1603,
         ERROR_CANCELLED = 1223,

Bloxstrap/Utilities.cs

@@ -1,9 +1,18 @@
 using System.ComponentModel;
+using System.Security.Principal;
 
 namespace Bloxstrap
 {
     static class Utilities
     {
+        /// <summary>
+        /// Is process running as administrator
+        /// https://stackoverflow.com/a/11660205
+        /// </summary>
+        public static bool IsAdministrator =>
+           new WindowsPrincipal(WindowsIdentity.GetCurrent())
+               .IsInRole(WindowsBuiltInRole.Administrator);
+
         public static void ShellExecute(string website)
         {
             try