Really disallow us from running under elevated UAC

src/Setup/winmain.cpp

@@ -46,18 +46,12 @@ int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
 
 	bool isQuiet = (cmdLine.Find(L"-s") >= 0);
 	bool weAreUACElevated = CUpdateRunner::AreWeUACElevated() == S_OK;
-	bool explicitMachineInstall = (cmdLine.Find(L"--machine") >= 0);
+	bool attemptingToRerun = (cmdLine.Find(L"--rerunningWithoutUAC") >= 0);
 
-	if (explicitMachineInstall || weAreUACElevated) {
-		exitCode = MachineInstaller::PerformMachineInstallSetup();
-		if (exitCode != 0) goto out;
-		isQuiet = true;
-
-		// Make sure update.exe gets silent
-		if (explicitMachineInstall) {
-			wcscat(lpCmdLine, L" --silent");
-			printf("Machine-wide installation was successful! Users will see the app once they log out / log in again.\n");
-		}
+	if (weAreUACElevated && attemptingToRerun) {
+		CUpdateRunner::DisplayErrorMessage(CString(L"Please re-run this installer as a normal user instead of \"Run as Administrator\"."), NULL);
+		exitCode = E_FAIL;
+		goto out;
 	}
 
 	if (!CFxHelper::CanInstallDotNet4_5()) {
@@ -88,6 +82,7 @@ int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
 		wchar_t buf[4096];
 		HMODULE hMod = GetModuleHandle(NULL);
 		GetModuleFileNameW(hMod, buf, 4096);
+		wcscat(lpCmdLine, L" --rerunningWithoutUAC");
 
 		CUpdateRunner::ShellExecuteFromExplorer(buf, lpCmdLine);
 		exitCode = 0;