How can I wait to the close of the uninstall panel in windows 7 from batch file?

Question

I have simple batch file :

@echo off
call "c:\windows\system32\appwiz.cpl"
echo "Done"

On Windows XP, this batch launche the uninstall panel of windows, and block the execution until the use close the panel.

The same batch on Windows 7 doesn't blocks anymore, the echo is displayed immediatly.

How can I make the script blocks again on 7 ?

Thanks.