It helps to know when and where it pops up. Open Internet Explorer, go to
Tools, select Internet Options, go to the Advanced tab, place a check next
to script debugging and make sure there is no check next to "Display
notification about every script error," click apply and ok.
Script debugging is used by web page designers to make sure everything is
functioning properly with the web pages they design. Unfortunately, it is
turned on by default in XP and every time a user goes to a web site where
there are errors on the page they are notified if this feature is turned on.