You can make this window modal if you select CTRL - I (VI Properties) and go under window appearance selection. Then select "customize". Inside this window you will see the settings to allow you to keep this window up infront of all other LV windows by selecting "modal" under window behavior. This doesn't help with other applications though, It will only work for LV, but you can do some little tricks. 1 trick that helps is to Size the front panel to the size of the entire screen and hide the windows taskbar. Now this doesn't prohibit a user from selecting ALT Tab to switch applications so you will have to disable these keys using something like this: http://sine.ni.com/apps/utf8/niepd_web_display.display_epd4?p_guid=B45EACE3E7DF56A4E034080020E74861. Keep in mind this is one solution and there are others by using windows DLL options. Hope this helps.
