Internet Explorer (6 and 7)
Select Tools | Internet Options… menu item from the main menu.
Change to the Security tab at the top of the Internet Options window that pops up.
From the list of zones at the top of the Security options select the internet icon.
Select the button near the bottom that reads Custom Level.
In the new window that pops up, scroll down to the item that reads Active Scripting.
Select the option marked Enable.